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THE CUPOLA FURNACE 



THE CUPOLA FURNACE 

A PRACTICAL TREATISE ON THE 

CONSTRUCTION AND MANAGEMENT 

OF 

FOUNDRY CUPOLAS: 

COMPRISING 

IMPROVEMENTS IN CUPOLAS AND METHODS OF THEIR CONSTRUCTION AND MANAGE- 
MENT; TUYERES; MODERN CUPOLAS; CUPOLA FUELS; FLUXING OF IRON; GETTING 
UP CUPOIA STOCK; RUNNING A CONTINUOUS STREAM; SCIENTIFICALLY 
DESIGNED CUPOLAS; SPARK-CATCHING DEVICES; BLAST-PIPES AND 
BLAST: BLOWERS; FOUNDRY TRAM RAIL, ETC., ETC. 

BY 

EDWARD KIRK, 

PRACTICAL MOULDER AND MELTER, CONSULTING EXPERT IN MELTING. 

Author of " The Fouvding of Metals" and of Numerous Paf-ers on Cupola Practice. 

ILLUSTRATED BY ONE HUNDRED AND SIX ENGRAVINGS. 

THIRD THOROUGHLY REVISED AND PARTLY RE-WRITTEN EDITrON. 



PHILADELPHIA : 

HENRY CAREY BAIRD & CO., 

INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS, 
810 Walnut Street. 

LONDON : 

E. & F. N. SPON, Ltd., 

57, Haymarket, S. W. 

1910. 






"^.1 



Copyright, 1910, 

BY 

EDWARD KIRK. 



^ 



Printed by the 

WICKERSHAM PRINTING COMPANY, 

111-117 East Chestnut f-treet, 

Lancaster, Pa., U. S. A. 



^QlA2li8d24 



PREFACE TO THE THIRD EDITION. 



The second edition of The Cupola Furnace having been 
for some time exhausted, while the demand for the book con- 
tinues unabated ; and urgent requests being constantly received 
from foundrymen for additional information in this important 
department of the industry are the inducements which have 
led to the preparation of this new and revised issue. 

This, the third edition, has been greatly improved by a re- 
arrangement of chapters and a more appropriate classification 
of subjects. Its scope and usefulness for the particular branch 
of business for which it is intended, have been much extended 
by replacing, with entirely new and up-to-date matter, the sec- 
tions relating to foundry irons, foundry chemistry and other 
subjects, which have been omitted because they do not directly 
pertain to cupola manipulation. The new matter, it may be 
stated, comprises about 200 pages and includes instructive, 
illustrated details of cupola accessories and cupola manage- 
ment. 

Many founders are to-day in experimental work going over 
the same ground that has been exploited for years, and in 
order that they may learn what has already been done in this 
direction, and thus save themselves unnecessary expense, it 
has been deemed advisable to describe and illustrate a number 
of scientifically designed cupolas and tuyere-arrangements of 
the past. 

It is confidently believed that a careful study of the follow- 
ing pages can hardly fail to arouse in the founder, the foreman, 
and the melter, a realization of the far-reaching importance of 
an intelligent system of cupola practice and that only by, and 
through, such a system can be obtained, at a minimum cost, 

(v) 



vi PREFACE TO THE THIRD EDITION. 

an iron indicated by the quality of the iron melted and pos- 
sessing the properties required for the work to be cast. 

In conclusion, it only needs to be added, that as is the cus- 
tom of the publishers, in all cases, they have provided the 
work with a copious table of contents as well as a very full 
index, which will render reference to any subject in it, at once, 
prompt, easy and satisfactory. 

Edward Kirk. 

Philadelphia, August, 1910. 



CONTENTS. 

CHAPTER I. 
The Cupola Furnace. 

PAGE 

Advantages of the cupola furnace for foundry work; Quantity of fuel 
required for melting iron in various kinds of furnaces; Attempts to 
decrease the amount of fuel consumed in a cupola by utilizing the 
waste he&t 1 

Description of the cupola furnace; Forms and sizes of cupolas; Founda- 
tion of a large cupola .......... 2 

Advantage of iron supports over brick work; Height of the bottom of 
the cupola; Pit beneath the cupola ....... 3 

Bottom plate; Bottom doors; Support of the doors; Various devices for 
holding the doos in place; Construction of the casings ... 4 

Stack casing; Construction of the stack; Tuyere holes . . • . 5 

Location of the charging door and its construction; Lining of the casing 
and materials used for it . . 6 

The scaffold and its location; Size of the scaffold 7 

CHAPTER IL 

Improvements in Cupof.as. 
Type of the first cupola furnaces used in this country, and mode of con- 
structing them; Cupolas in the foundry of Chas. Reeder & Sons, Bal- 
timore, Md 8 

Construction of these cupolas 9 

Objection to the draw-front cupola 10 

First use of the drop bottom; General mode of building cupolas . .11 

Supply of blast; Location of tuyeres 12 

Cause of slow melting of old-fashioned cupolas; Heights of cupolas; 

Boiler-plate casings for both cupola and stack ..... 13 
Increase in the size of tuyeres; Lowering of the tuyeres to from 4 to 10 

inches above the bottom; Introduction of the Mackenzie cupola . 14 
Abandonment of the old theory of driving blast to the center of the 
cupola by force of the blower and small tuj-eres; Introduction of cast 
iron tuyere boxes; Objectionable features of the Mackenzie cupola . 15 
Introduction of the Truesdale cupola; The Lawrence cupola . .16 

(Vii) 



Vin CONTENTS 

PAGE 

The Pevie cupola; The Dougherty tuyere ...... 17 

Introduction of the Colliau plain round cupola, and its complete failure. 18 
Application of the system of tapping slag to cupolas; Change in the 
form of cupola supports, bottom doors, air chambers; Previous use of 

the double row of tuyeres ....•..,. 19 

Advantage of the double row of tuyeres 20 

Return to the plain round cupola of forty years ago . . . .21 

CHAPTER III. 
Constructing a Cupola. 

Proper location of a cupola; The scaffold . . • 22 

Conveyance of coal or coke to the scaffold; Cupola foundation and its 
construction , .... 23 

Prevention of uneven settling and breaking of the bottom; Brick walls 
for the support of a cupola; Best supports for a cupola . . .24 

Height of cupola bottom; Provision for the removal of the dump; Bot- 
tom doors ............ 25 

Devices for raising the bottom doors ....... 26 

Casing; Material for the casing or shell of the modern cupola and stack; 
Strain upon the casing 27 

Contraction of the stack; Prevention of sparks; What constitutes the 
height of a cupola; Utilization of the waste heat 28 

Table giving the approximate height and sizes of doors for cupolas of 
different diameters; Charging door; Air chamber . . . .29 

Construction of the air chamber when placed inside the casing, and 
when placed upon the outside of the shell; Objection to the round or 
overhead air chamber .......... 30 

Admission of blast to the air chamber; Location and arrangement of the 
air chamber when the tuyeres are placed high; Tap hole . . .31 

Arrangement when two tap holes are required; The spout and its con- 
struction 32 

Tapping slag; Location of the slag-hole 33 

Tuyeres; Number of tuyeres for small cupolas; Size of combined tuyere 
area; Tuyere boxes or casings 34 

Height at which tuyeres are placed in cupolas; Objection to high 
tuyeres ............. 35 

Two or more rows of tuyeres; Arrangement of a large number of tuyeres; 
Area of the rows; Increase in the melting capacity with two or three 
rows of tuyeres 36 

Lining; Materials for lining the casing; Grouting or mortar for laying 
up a lining; Manner of laying the brick ...... 37 

Thickness of cupola linings; Stack lining 38 

Arrangement of brackets; Preference by many of angle iron to brackets; 
Mode of putting in angle irons 39 



CONTENTS. IX 

PAGE 

Reduction of the lining by burning out; Settling of the lining; Mode of 
reducing the size and weight of the bottom doors and preventing the 
casing from rusting off at the bottom ....... 40 

Prevention of the absorption of moisture into the lining; Illustration of 
the triangular-shaped tuyere in position in the lining; Form of bottom 
plates; Fire-proof scaffolds 41 

Exposure of the scaflFold and its supports to fire; Devices to make scaf- 
folds fire-proof 42 

Novel plan of construction of a scaffold and cupola house in Detroit, 
Mich.; Best and safest scaffolds 43 

Cupola scaffolds in the foundries of Gould & Eberhardt, Newark, N. J., 
and of The Straight Line Engine Company, Syracuse, N. Y. . . 44 

CHAPTER IV. 

CupoivA Tuyeres. 

Mode of supplying the cupola furnace with air; Admission of the air 

through tuyeres or tuyere holes; Former and present melting capacity 

of a cupola; Epidemics of tuyere invention ...... 45 

The round tuyere; Arrangement of round tuyeres in the old-fashioned 

cast-iron stave cupola .......... 46 

Oval tuyere; Expanded tuyere ......... 47 

Doherty tuyere ............ 48 

Sheet blast tuyere; Mackenzie tuyere ....... 49 

Blakeney tuyere . . . . . . . . . . . . 50 

Horizontal and vertical slot tuyere ........ 51 

Reversed X-^uyere; Truesdale reducing tuyere . . . . .52 

Lawrence reducing tuyere .......... 53 

Triangular tuyere; Results of melting with this tuyere obtained by The 

Magee Furnace Company, Boston, Mass.; Water tuyere . . .54 

Colliau tuyere; Whiting tuyere; Chenney tuyere 56 

The double tuyere; Mode of placing the tuyeres in Ireland's cupola; 

Claims for the double tuyere ......... 57 

Consumption of fuel in a double tuyere cupola; Three rows of tuyeres; 

Cupola constructed by Abendroth Bros., Port Chester, N. Y. . . 58 
Theory of producing heat by consuming the escaping gases from the 

combustion of fuel; Greiner tuyere . . . . . . .59 

Adjustable tuyeres; Cupola of the Pennsylvania Diamond Drill and 

Manufacturing Co., Birdsboro, Penna 60 

Bottom tuyeres 61 

Mode of covering the mouth of a bottom tuyere 62 

Early use of the bottom tuyere; Bottom tuyere patented by B. H. Hib- 

ler; Thomas D. West on the bottom tuyere ...... 63 

Size of tuyeres; Mistake made by foundrymen in regard to the size of 

tuyeres; Tuyere of the old-fashioned cupola . ..... 64 



X CONTENTS. 

PAGE 

Size of the combined tuyere area of a cupola; Height of tuyere; Great 

difference of opinion on this subject <>'T 

Experiments with tuyeres at various distances above the sand bottom; 
Experiment to soften hard iron by bringing the molten metal in con- 
tact with charcoal; Reason given in favor of high tuyeres . tjii 
Tuyeres in stove foundries; Location of tuyeres in smaller cupolas . (57 
Tuyeres in machine and jobbing foundry cupolas, and in cupolas for 
heavy work . . . . . . . . • ■ • . HS 

Number of tuyeres; Objection to the use of only one tuyere; Two 

tuyeres sufficient for the largest cupola in use 69 

Arrangement of a double row of tu\eres; Sliape of tuyeres . . .70 
Tuyeres to improve the quality of iron; Tuyere boxes . .71 

New tuyeres; Causes of success and of failure; Tuyeres not the only 

factor in successful cupola practice 72 

The Watt cupola tuyeres 73 

The Zippier tuyere; The Kuoeppel tuyere 75 

CHAPTER V. 
Cupola Management. 

Necessity of learning the peculiarities in the working of a cupola; A 

cupola cannot be run by any given rule or set of rules; Drying the 

lining ....•• ......'' 

Drying a backing or filling between the casing and lining; Putting up 

the doors; Devices for raising the doors into place 78 

Support of double doors; Sizes of props to support the bottom . 79 

Ring attachment to the prop; Superstition of older melters regarding 

the prop; Dropping the doors; Modes of releasing the prop . . SO 

Sand bottom; Sand employed for this purpose. Objection to clay sands 

and other sands; Sand which makes the very best kind of bottom . 81 
Wetting the bottom sand; Bringing the sand into the cupola . . . 82 

Cause of leakage in the sand bottom Sr! 

Boiling of iron due to a wet bottom; Pitch or slope of the bottom . . 84 
Effect of a high pitch; Change in the action of the iron at the spout by 

the pitch of the bottom; How the bottom should be made . . .85 
Slope of the bottom in cupolas with two tap holes; Spout; Spout lining 

material ^^ 

Effect of the use of too much clay or too much sand in the lining; Mode 

of making up the spout lining ^7 

Building up the sides of the lining; Place of the greatest strain upon 

the spout lining ^^ 

Proper shape of the spout lining; Cause of pools of iron forming in the 

spout; Removal of slag from the sprut 89 

Front; Material used for putting in the front; Mode of putting in the 

front 90 



CONTENTS. XI 

PAGE 

Effect of making the front material too wet; Troubles due to poor front 
material ............. 91 

Sizes of tap holes; Locating the tap holes ....... 92 

Slag hole 93 

Slag hole front; Chilling of slag in the tap hole . . . .94 

Lighting up; Mode of placing the wood and shavings in the cupola; 

Putting in the bed fuel 9.S 

Effect of carelessness in arranging the wood and lighting up . . . 96 
New method of lighting up; The Buckeye Heater or oil torch . . 97 
The bed; The melting point or melting zone in a cupola; Determina- 
tion of the exact location of the melting zone; Necessity of discover- 
ing the melting-point in order to do good melting .... 98 

To find the melting-point .......... 99 

Cause of trouble in melting after a cupola has been newly lined; Fuel 
required for a bed in cupolas of different diameters; Charging; Old 
way of loading or putting the fuel and iron into a cupola . . 109 

Modern way of stocking a cupola; Correct theory of melting iron in a 

cupola; Practical woiking of a cupola upon this theory . . . lUl 
Effect of too heavy charges of iron and of too heavy charges of fuel; 
Variations in the weight of the first charge of iron in proportion to 

the weight of the bed 102 

Variations in the per cent, of iron to fuel; Placing the charges . . 103 
Mode of placing the pieces of pig or other iron; Distribution of the 

charge of fuel; First step in mixing irons when melted in a cupola . 104 
Placing the pig iron when melting with remelt scrap .... 105 

Charging whtn melting old scrap and pig; Charging additional iron; 
Bad charging as a cause of poor melting ...... lOH 

Charging flux; On what the quantity of flux depends .... 107 

Blast; The old and modern ways of giving blast to the cupola; Blast 
phenomena; Melting .......... lOH 

When melting I egins in a cupola; Difference of opinion as to the time 
of charging the iron before the blast is put on ..... 109 

Best way to put on the blast; Chilling and hardening of the first iron; 
Running off a heat without stopping in; Mode of reducing the size of 

the tap hole 110 

No advantage in holding molten iron in a cupola to keep it hot; Proper 
management of hand-ladle work ........ Ill 

Indication of how the cupola is melting by the flow of iron from the 
tap hole; Poking the tuyeres ......... 112 

Fuel; Amount of fuel required in theory and in practice . .113 

Necessity of keeping an accurate account of the amount of iron melted; 
Chief olject of mtlting in a cupola . . . . . . .114 

The old story of "not enough blast; " Necessity of an even volume of 
blast; Tapping bars; Shapes and sizes of tapping bars . . . . 115 

Steel bar for cutting away the bod before tapping; Bod sticks . .116 



XU CONTENTS. 

PAGE 

Combination stick; Objection to this stick; Number of bod sticks for 
each cupola; Bod material; Importance of the material of which the 

bod is composed 117 

Loams for bods; Mixture for a good bod; Bod for small cupolas . .118 
Qualities of a good bod; Tapping and stopping in; Mode of making the 

bod 119 

How to make the tap; Mode of stopping in 120 

The skill of the melter seen at the tap hole; Uneven melting the fault 

of the melter 121 

Dumping; Removal of the props; Starting the sand bottom . . . 122 
Bridging over in small cupolas above the tuyeres, and mode of remov- 
ing the bridge; Various methods of handling the dump . . . 123 
Removing the dump, and various devices for this purpose; Breaking up 
and picking it over; Different ways of recovering the iron from the 

dump 124 

Chipping out; Theory of some melters to prevent iron from running 

into the tuyeres; Objection to this theory 125 

Cupola picks; Daubing; Materials for this purpose 126 

Soaking fire clay ........... 127 

Amount of sand required for mixing with the clay; No advantage in 
using a poor cheap daubing; Shaping the lining; Object of applying 

daubing . . 128 

Mode of making new linings; Chipping off cinder and slag that adhere 
to the lining over the tuyeres; No necessity for filling in the lining at 
the melting zone and making it perfectly straight .... 12!» 

Objections to sudden offsets or projections; Thickness of the daubing; 
Sectional view of a cupola illustrating effect of excessive daubing . 13(( 

Shaping the lining of the boshed cupola l;i2 

Special directions required for shaping and keeping up the lining of 
patent and odd shaped cupolas; Relining and repairing; Thickness of 
the lining; Location of the greatest wear of the lining; Destruction 

of the lining at and below the tuyeres 13;^ 

Length of time a cupola lining will last; Burning away of the lining; 
Thickness of lining required to protect the casing; Repairing the 

lining at the melting zone 134 

Repairing a lining with a split brick; Mode of making a split brick; An 
excellent daubing material . . . . . . , . .135 

CHAPTER VI. 
Modern Cupoi.as. 

Interesting fact in connection with modern cupolas; Importance of 

high cupolas for fast and economical melting; CoUiau cupolas . . 137 
Standard CoUiau cupola furnace ... .... 138 

The Newten cupola 141 



CONTENTS. ' xiii 

PAGE 

Paxson Colliau cupola 144 

Indestructible wire screen charging door of this furnace . . . . 147 

The Whiting cupola 148 

The E. J. E. cupola 150 

Points of special merit of the E. J. E. cupola 151 

Calumet cupola ............ 15:i 

CHAPTER VII. 

Largk Cupolas. 

The Homestead large cupolas of the Carnegie Steel Works; Dimensions 
of these cupolas . . . . . . . . . . . 15<> 

Shape of lining of very large cupolas; The McShane large cupola . . 157 
Non-success of this cupola and causes of uneven melting in it . . 158 
The Thos. D. West large cupola; Trouble with the center blast of this 

cupola 159 

Plan of making large cupolas melt at the center; How a diameter of 55 
to 60 inches at the tuyeres may readily be obtained in cupolas of 
larger size without danger of bridging or hanging up .... 160 
Advantages and disadvantages of large cupolas . . . . .161 

CHAPTER VIII. 

Smali. Cupolas. 

General use of small cupolas in the early days of foundry practice in 
this country; Gradual increase in the size of cupolas .... 1G4 

Necessity of testing a new brand of mixture of iron; Value of the small 
cupola for various purposes ......... 165 

Swivel cupolas; Small cupola in use at the foundry of Charles Spangler, 

Allentown, Pa 166 

A portable small cupola .......... 168 

A cheap small movable cupola . . . . . . . . .170 

Management of a small cupola; The Keep sectional cupola . . . 171 
Advantages claimed for this cupola . . . . . . . . 1 73 

Stationary bottom cupola 174 

Small cupolas for bedstead work . . . . . . . .175 

Cupola on wheels; Paxson truck and track cupola . . . . .177 

Small cupolas of Europe; Smaller cupolas used throughout the mid- 
lands of Great Britain and in the small foundries of Belgium and 
France 178 



XIV CONTENTS. 

PAGE 

CHAPTER IX. 

Examples of Bad Melting. 
Necessity of knowing causes of poor melting; Trouble with the cupolas 

at the stove foundry of Perry & Co., Sing Sing, N. Y. . . . IS] 

Cause for the trouble 182 

Sectional views of linings out of shape ....... 183 

Remedy for the troubles .......... 188 

Bad melting at a West Troy stove works; Visit to the foundry of Daniel 

E. Paris & Co., West Troy, N. Y.; Inspection of the foundry with a 

view of locating the trouble ......... 19li 

Trouble due to the use of too much fuel ....... 10] 

Experiment of running the cupola with less fuel; Objection of the 

melter to the experiment ......... 191' 

Result of the experiment 19o 

Heats with a still further reduction of fuel 194 

Cause of bad melting in this foundry ....... 19/) 

Warming up a cupola; Visit to the plant of the Providence Locomotive 

Works, Providence, R. I.; Trouble with the cupola .... 19H 
Cause of the poor melting due to the bed being burned too much . . 197 
Remedy of the trouble; Bad melting caused by wood and coal ; Cause of 

poor melting in one of the leading novelty foundries in Philadelphia. 198 
Poor melting in a Cincinnati cupola; Sectional elevation showing the 

condition of the cupola 199 

Uneven burning of the bed; Reason for the necessity of dumping a 

cupola at the foundry of Perry & Co 201 

CHAPTER X. 

Hot-Blast Cupolas. 
Early attempts to applj' the hot blast to cupola practice; Fallacy of the 

theory; Utilization of the heat from the cupola or of that escaping 

from the cupola stack; Method of utilizing this heat as applied by 

Jagger, Tread well & Perry, at Albany, N. Y .202 

Failure of this plan 204 

Arrangement for supplying a hot blast to the cupola with no expense 

for heating the blast; The Colliau hot-blast cupola .... 205 

The Holland cupola 20ti 

Results obtained from the use of the Holland cupola; Analysis of the 

claims; Objection to heating blast in the way proposed . . . 208 
Oil in cupola practice; Use of oil in the Holland cupola; Advantages 

claimed for the Holland cupola . . . . . . . 209 

P.aillot's cupolas; Theory of oVjtaining a hot blast for a cupola . . 210 
Claims made for the Baillot cupola by the manufacturers . .211 

Record of experiments mane on a cupola of the Baillot system situated 

in the foundry of the Canada Car Co., Turcot Village . . . .214 



CONTENTS. 



PAGE 

CHAPTER XI. 



Freezing the Bi.ast. 

Success in the saving of fuel by freezing the blast to drive out anj- 
moisture it may contain by blast furnace men; Difference between this 
practice in furnaces and in cupolas; Claim of hotter iron being ob- 
tained in winter; Mode of freezing the blast. ..... 215 

Moisture in blast; Experiments made at The Lobdell Car Wheel Co., 

Wilmington, Del 216 

Various methods of giving a moist blast; "Weather and the output of 
the cupola," by M. H. Bancroft; Air capacit}' for moisture . .217 

Effect of heat on air . . 218 

Load on blower or fan . . 219 

Temperature of the air; Ratio of air and coke . . . . . 22(1 

Temperature and moisture; Coke in summer and winter . . , . 221 
"Moist or dry cupola blast," by Dr. Edward Kirk: Adding steam or 

water to blast . .222 

Climate and hot iron; "Dry air for the cupola," comments by the 
Editor of "Castings". . . 228 

CHAPTER XII. 
Cupola Euel.s. 

Coke Ihe best cupola fuel; Gas and liquid fuels; Reason why these fuels 

cannot be used in a cupola . 225 

Experiments of melting iron in a cupola with gas and liquid fuels. . 226 
Failure to produce a hot fluid iron ........ 227 

Charcoal fuel; Superiority of iron produced with this fuel . 228 

Mode of charging when melting with charcoal; Weight of charges of 
fuel and iron ............ 221i 

Anthracite coal as a cupola fuel; Pennsylvania hard coal fields . . 23(1 
Difference in coal from the various mines in the same region; Opening 
of the first mine in the Pennsylvania districts . . . . . 231 

Charging and melting with coal ........ 232 

Heat melted with Old Mine Lehigh coal; Considerable variation in the 
per cent, of coal consumed in melting ....... 233 

Per cent, of coal consumed in melting for one year at different found- 
ries; Size of coal used in melting . . ... . . . 234 

Best results obtained in melting with coal . . . . . . 235 

Mixture of coal with coke; Manner of charging and melting with mixed 

fuels 236 

Heat melted in a 54-inch Whiting^ cupola with Schuylkill coal and Con- 
nellsville coke. ........... 237 

Cupola coke; First coke made in ovens; First shipment of coke . • 238 
Practice of foundrymen making their own coke ..... 239 



xvi CONTENTS. 

PAGE 

Various grades of coke; Cause of failures in making coke; Superiority of 

the coal of the Counellsville region for the manufacture of coke. . 240 
Use of gas-house coke for small heats; Requirements for the manufac- 
ture of a good foundry coke 241 

Early practice in melting with coke 242 

Mode of judging the melting qualities of a coke; Number of pounds of 
iron melted to pounds of fuel; Variation in the quality in the early 

days of coke 24H 

Cause of the variations in the quality of coke; Best cupola coke; 72- 
hour coke ............ 244 

Manner in which iron is melted in a cupola furnace .... 245 

Mistake by melters who do not understand the space theory of a cupola; 
Theory of melting which should be followed by every founder melting 
with coke. ............ 24t> 

Remedy in melting when coke is poor; Rule of charging coke and iron. 247 
Weight of coke required for a bed; Measurement and weight the best 
guides for bed and charges ......... 248 

Watching the melting for indications of necessary changes . . . 249 
Difference of opinion as to the per cent, of coke to iron; Reports of 

melting with Counellsville coke and what is indicated by them. . 250 
By-product coke; Extensive use of by-product coke; Properties of by- 
product coke 251 

Bituminous coal as a cupola filel; Experience in melting with this fuel. 252 
No deterioration in the quality of iron by the coal ..... 258 
Selection of coal; A wonderful cupola; Mr. Herbert M. Ramp on this 

subject . . • 254 

Comments on this wonderful cupola or melting record .... 255 

CHAPTER Xin. 
Fluxing of Iron in Cupolas. 

Definition of a flux; Substances used as fluxes; Purpose of the use of 
limestone in the production of pig iron 25H 

On what the making of a brittle cinder in a cupola by the use of lime- 
stone depends; Limestone in large quantities ..... 25i> 

Variation in the quantity of limestone required to produce a fluid slag; 
Weight of slag drawn from a cupola 2H(li 

Constituents of the slag; Effect of flux upon iron; The action of fluxes 
on lining . . . . , 261 

How to slag a cupola; Cause of trouble in slagging; General method of 
charging the limestone; The slag hole 26;i 

Slag in the bottom of a cupola; Importance of the time for drawing the 
slag; Does it pay to slag a cupola ? Estimate of the cost of slagging . 264 

Shells; Use of oyster, clam and other shells; Cause of the crackling 
noise of shells when the heat first strikes them; Marble spalls . . 265 



CONTENTS. xvii 

PAGE 

Experiments with mineral and chemical materials with the view of 
making a cheap malleable iron; Reason why iron is often ruined as a 
foundry iron by improper melting and fluxing ..... 266 

Effect of silicon on iron; Per cent, of silicon an iron may contain; Use 
at the present time of a large amount of high silicon cheap Southern 
iron 267 

Heav}' breakage due to the use of high silicon iron; Effect of carbon 
upon cast iron; Removal of free carbon from iron 268 

Fluor spar and its use as a flux ......... 269 

Cleaning iron by boiling; Poling molten iron 270 

CHAPTER XIV. 

What a Cupola will Melt. 

Chief use of the cupola furnace; Employment of the cupola furnace for 
other purposes than melting iron; Quantity of cast iron that can be 

melted in a cupola . 272 

Number of hours a cupola may be run; Size and weight of a piece of 
cast iron that can be melted in a cupola; Charging large pieces of iron 
at the foundry of the Pratt & Whitney Co., Hartford, Conn.; Melting 
of cannon and other heavy government scrap at the Lobdell Car 
Wheel Co., Wilmington, Del.; Melting large pieces of iron. . . 273 

What should be done when the iron comes dull 274 

Melting tin plate scrap in a cupola; Recovery of tin deposited upon the 

iron; Quality of the molten metal from this scrap 275 

Experiments in melting this scrap ........ 276 

Melting scrap sheet iron and galvanized sheet iron scrap; Melting tin- 
plate scrap 277 

Construction of a cupola expressly for melting tin-plate scrap . . 278 
Amount of profit in melting this scrap; Melting brass in a cupola; Ad- 
vantages presented by the cupola for this purpose .... 279 

CHAPTER XV. 

Art in Melting. 

The art of melting iron in a cupola but little understood by many 
foundrymeu and foundry foremen; Troubles experienced in melting . 280 

No chance work in nature or in art; Necessity of understanding the con- 
struction and mode of operation of a cupola to do good melting. . 281 

Location and arrangement of the tuyeres; Preparation of the cupola for 
a heat; Ivighting up 282 

Melting iron in a cupola a simple process; Things to be learned and 
practiced; Necessity of a close study of all the materials used in melt- 
ing • 283 



XVlll CONTENTS. 

PAGE 

What should be the aim of every moulder; Advisability of the foreman 
of a foundry being the melter; Duties of the melter .... 284 

Taking off the blast during a heat 285 

Banking a cupola; Mr. Knoeppel, Foundry Superintendent, Buffalo 
Forge Co., Buffalo, N. Y., on this subject 286 

Give the melter a chance; Respect due to the practical and scientific 
melter; Unfortunate position of a poor melter . ... 288 

Interference with a good melter frequently the cause of poor melting; 
Necessity of furnishing proper tools for chipping out, and making up 
the cupola 289 

What should be the aim of every melter; Interest of every foundryman 
to keep his melter posted 290 

CHAPTER XVI. 

The CupoivA Accounts. 

Value of cupola accounts; Manner of keeping the accounts . . . 291 

Cupola report of Abendroth Bros., Port Chester, N. Y 292 

Cupola report of Byram & Co., Iron Works, Detroit, Mich. . . . 293 
Daily report of Foundry Department, Lebanon Stove Works . . . 294 

Melting sheet of Syracuse Stove Works 295 

Report of castings in Shop 296 

Cupola slate for charging and cupola report 297 

Blanks for reports and records, and mode of making them out; Report 
on a slate; Correctness essential to the value of a cupola account; Cost 

of melting 298 

Unreliability of melting accounts as generally kept; Objection to meas- 
uring fuel in baskets; Result of a supposed accurate account of the 

melting in a foundry in New Jersey 299 

Proper method of figuring the cost of melting per ton .... 300 

CHAPTER XVII. 

EXPI.OSION OF Moisten Iron. 

Conditions under which molten iron is explosive; Explosions caused by 
a wet spout or a wet bod 302 

Cause of sparks; Various causes of the explosion of molten iron; Ex- 
plosion due to thrusting a piece of cold, wet or rusted iron into 
molten iron 303 

Explosion of molten iron when poured into a damp or rusted chill- 
mould or a wet sand mould; Accident in the foundry of Wm. McGil- 
very & Co., Sharon, Pa. 304 

Explosion of molten iron when poured into mud or brought in contact 
with wet rusted scrap; Accident in the foundry of James Marsh, 



CONTENTS. xix 



Lewisburg, Pa.; Accident at the foundry of North Bros., Philadel- 
phia, Pa 305 

Explosions at the foundry of the Skinner Engine Co., Erie, Pa., and at 
the Buffalo School Furniture Co., Buffalo, N. Y 306 

Prevention of explosions 307 

CHAPTER XVIII. 
Getting up Cupola Stock. 

Oldest and original way of placing stock upon a cupola scaffold; Wheel- 
barrow runways ........... 308 

Track runways; Elevators 309 

The steam-hydraulic elevator manufactured by The Craig Ridgeway & 

Son Co. 310 

Lifting magnets , 311 

Crane with magnet attached used at the Baldwin Locomotive Works, 
Eddystone, Pa. ; Elevated stock yards; Stock yard of the Browne & 
Sharp Manufacturing Co., Providence, R. I. 313 

CHAPTER XIX. 
Running a Continuous Stream. 

Advantages of running a continuous stream; Double spout; Device used 

at the Osborne Mower & Reaper Co., Auburn, N. Y 315 

Basin spout; Cross spout in use at the foundry of The Lobdell Car Weeel 

Co., Wilmington, Del 316 

Neat method of disposing of slag 317 

Application of the cross spout to various purposes; Spout ladle . . 318 
Reservoir spout ladle; J. W. Paxson Co. reservoir ladle .... 320 
Tapping ladle; Advantages and disadvantages of this system . . . 321 
Another plan for running a continuous stream. . ' . . . . 322 

CHAPTER XX. 
Number of Men Required to Man a Cupola. 

Various conditions on which the amount of labor required depends; Mr. 

J. W. Keep's investigations and report 323 

Summary of the melt compared with the necessary charging-floor labor. 324 
Devices for charging cupolas; Mode of charging at the plant of the 

Carnegie Steel Works, Homestead, Pa. ... . • . 325 

Endless chain carrying and charging device; English charging device; 

Use of the lifting magnet for charging ....... 326 

Small charges for cupolas; Dr. Moldenke on this subject; Theory that 

every cupola is a law to itself; How the best results from a cupola are 

obtained 327 



XX CONTENTS. 



Retaining heat in a foundry; Locations of cupolas in foundries; Preven- 
tion of waste of heat; Cupola dampers ....... 328 

Protecting the melter when chipping out, and devices for this purpo.se. 329 
Pig bed; Iron pig moulds; Construction of a pit-pig bed for pigging out; 
Protecting the pig bed .......... 330 

Boiling or foaming slag .......... 831 

Treatment of Inirns; New method of mixing daubing .... 332 

Advantages of this method; Another way of mixing daubing . . . 333 
Renewing a lining; Mica schist lining ....... 334 

Common red brick lining .......... 335 

Moor's patent cupola breast and runner ....... 336 

CHAPTER XXI. 

SCIENTIFICAI,I.Y DESIGNED CuPOLAS. 

Scientific points presented by the various shaped linings, arrangement 
of tuyeres and distribution of blast; Objections to these scientific, 
fancy-designed cupolas .......... 337 

Old style stave cupola in general use throughout the country many 
years ago. ............ 338 

Practice of casting with the use of the old style cupola .... 340 

Reservoir cupola; Expanding cupola 342 

Ireland's cupola . . 344 

Ireland's center blast cupola ......... 346 

Voisin's cupola 348 

Woodward's steam jet cupola 350 

Objection to this style of cupola; Tank or reservoir cupola . . . 354 
Production of soft iron by putting a quantity of charcoal on the sand 

bottom; Use of tanks in England 356 

Mackenzie cupola ........... 357 

Management of the Mackenzie cupola ....... 359 

Dr. Otto Gmelin's cupola 361 

Pevie cupola ............ 363 

Object of Mr. Pevie in constructing a cupola upon this plan; Stewart's 
cupola ............. 365 

Rapid melting in this cupola; The Greiiier patent economical cupola . 367 
Steam jet cupolas; Experiments in melting in a cupola with steam with 

and without blast 369 

Jumbo cupola ............ 371 

Charge table for the Jumbo cupola . 372 

Crandall improved cupola with Johnson patent center blast tuyere . 374 

Claims for this cupola; Blakeney cupola 376 

Preventing sparks from being carried out of the stack .... 377 



CONTENTS. XXI 

PAGE 

CHAPTER XXII. 
Spark Catching Devices for Cupoi^as. 

Spark catcher in old-style cupolas; Modern spark arrester . . . 379 
Return flue cupola spark catcher, designed by John O'Keefe . . • 382 

Other spark catching devices . 884 

The best spark catching device; Cupola hoods. ..... 385 

Various kinds of hoods 386 

CHAPTER XXIII. 

Cupola Straps. 

Brief paragraphs illustrating important principles; Terms used in differ- 
ent sections of the country to indicate the melting of iron in a cupola. 387 
Best practical results for melting for general foundry work . . . 391 
Remarks by Mr. C. A. Treat; Difficulty experienced by a fouudryman 
in obtaining reliable cupola reports for publication .... 392 

CHAPTER XXIV. 

Blast Pipes and Blast. 

Blast pipes; Importance of the construction and arrangement of blast 
pipes; Underground blast pipes; Objections to this arrangement. . 394 

Materials used in the construction of blast pipes; Galvanized iron pipes; 
Joints; Table prepared by the Buffalo Forge Co , Buffalo, N. Y., as a 
guide for increasing the diameter of pipes in proportion to the length. 395 

Table showing the necessary increase in diameter for the different 
lengths 396 

Diameter of blast pipes; Frequent cause of a blower being condemned 
as insufficient; Connection of blast pipes with cupolas . . . . 397 

Connecting blast pipes direct with tuyeres; Combined area of the branch 
pipes; Table of diameter and area of pipes ...... 398 

Perfect connection of air chambers; Poor arrangement of pipes . . 399 

Mode of connecting a belt air-chamber with the tuyeres; Best way of 
connecting blast pipes with cupola tuyeres 401 

Blower placed near cupola 402 

Poor melting often caused by long blast pipes; Perfect manner of con- 
necting the main pipe with an air chamber; Placing a blower; Con- 
venient way of placing a blower near a cupola ..... 403 

Blast gates; Advantage of the employment of the blast gate . . . 404 

Explosions in blast pipes; Prevention of such explosions; Blast gauges; 
Variety of gauges 406 

Indication of the pressure of blast; What an air-gauge to be of any value 
in melting must indicate 407 



XXll CONTENTS. 

PAGE 

Blast in melting; Means for supplying the required amount of air to the 

cupola; Machines for suppl3-ing the blast 408 

Relative merits of a positive and non positive blast. .... 409 
Amount of air required for combustion of the fuel in melting a ton of 

iron; Theory of melting in the old cupolas with small tuyeres . . 410 
Points to be remembered in placing tuyeres in a cupola; Best tuyere for 

large cupolas 411 

Size of the largest cupolas in which air can be forced to the center from 

side tuyeres; Cupolas of the Carnegie Steel Works, Homestead, Pa.; 

Experiments with a center blast tuyere 412 

Claims for the center blast 413 

CHAPTER XXV. 

Blowers. 

Types of blowers 414 

The Green patented positive pressure blower; Connersville cycloidal 

blower ............. 415 

Sectional view of this blower; Advantages of this arrangement . . 416 
Horizontal blower; Numbers, capacities, etc., of the cycloidal blowers . 419 
Vertical blower and engine on same bed-plate. . . . . . 420 

Blower and electric motor 421 

Root's rotary pressure blowers 422 

Root's horizontal pressure blower 423 

Garden City positive blast blower 424 

Claims made for this blower; Sturtevant high pressure blowers . . 425 

Principal parts of which the blower consists 426 

Piqua positive blowers; Fan blowers; Sturtevant blowers . . . 428 

Steel pressure blowers 429 

Steel pressure blowers on adjustable bed with combined upright engine. 430 
Electric steel pressure blowers ......... 431 

Buffalo steel pressure blower ......... 433 

How to obtain the best results from a blower of given size . . • 435 
Blower on adjustable bed with combined countershaft .... 436 

Buffalo blower for cupola furnaces in iron foundries .... 437 

Table of speeds and capacities as applied to cupolas; "A. B. C" steel 

pressure blowers of The American Blower Co 438 

Summary of the advantages of these blowers 439 

CHAPTER XXVI. 

Foundry Tramrail. 
Most efficient method of foundry transportation; Construction of the 

tramrail 442 

The tramrail as used in the average foundry; Dumping scrap and coke 

directly into the cupola 443 



CONTENTS. xxiii 



Insertion of a scale in the rail; The tramrail in foundries of larger 
capacities 444 

Saving in labor effected by the installation of an electric tramrail; Tram- 
rail for carrying molten metal from the cupola 445 

Provision for continuous pouring; Transportation of ladles . . .446 

Index 449 



CHAPTER I 

THE CUPOLA FURNACE 

The cupola furnace has many advantages over any other 
kind of furnace for foundry work. 

It melts iron with less fuel and more cheaply than any other 
furnace, and can be run intermittently without any great damage 
from expansion and contraction in heating and cooling. Large 
or small quantities of iron may be melted in the same furnace 
with very little difference in the per cent, of fuel consumed, 
and the furnace can readily be put in and out of blast. Con- 
sequently in all cases where the strength of the metal is not 
of primary importance, the cupola is to be preferred for foun- 
dry work. 

In the reverberatory furnace from ten to twenty cwt. of fuel 
is required to melt one ton of iron. 

In the pot furnace one ton of coke is consumed in melting 
a ton of cast iron, and two and a half tons in melting a ton of 
steel. 

In the blast furnace twenty to twenty-five cwt. of coke is 
consumed in the production of a ton of pig iron. 

In the cupola furnace a ton of iron is melted with from 172 
to 224 lbs. of coke. 

It will thus be seen that in the cupola furnace we have the 
minimum consumption of fuel in melting a ton of iron, although 
the amount consumed is still three or four times that theoret- 
ically required to do the work. 

Many attempts have been made to decrease even this small 
amount of fuel consumed in the cupola, by utilizing the waste 
heat passing off from the top for heating the blast. But the 
cupola being only intermittently at work has rendered ail such 
attempts futile. 



2 THE CUPOLA FURNACE. 

The cupola furnace is a vertical furnace consisting of a hollow 
casing or shell, lined with fire-brick or other refractory material, 
resting vertically upon a cast-iron bottom plate, having an 
opening in the center equal to the inside diameter of the lining 
and corresponding in shape to the shape of the furnace. This 
opening is closed with iron doors covered with sand when the 
furnace is in blast. Two or more openings are provided near 
the bottom of the furnace for the admission of air by draught 
or forced blast. A small opening, on a level with the bottom 
plate, is arranged for drawing ofif the molten metal from the 
iurnace. An opening, known as the charging door, is made in 
the side of the casing at the top of the furnace for feeding it 
with fuel and iron, and a stack or chimney is constructed 
above the charging door for carrying off the escaping smoke, 
heat and gases. 

Cupolas have been constructed cylindrical, elliptical, square 
and oblong in shape, and they have been encased in stone, 
brick, cast iron and wrought iron casings. From one to a 
hundred or more tuyeres have been placed in a cupola, and the 
stationary and drop bottoms have been used. At the present 
time cupolas are constructed almost entirely in a cylindrical or 
elliptical form, and the casing is made of wrought iron or steel 
boiler plate. The stack casing is made of the same material 
and is extended up to a sufficient height to give draught for 
lighting up, and to carry off the escaping heat and gases. The 
drop bottom has been almost universally adopted, at least in 
this country. 

Cupolas are constructed of various sizes, to suit the require- 
ments of the foundry they are to supply with molten metal. 
Those of large size are, when charged with iron and fuel, of 
immense weight, and require very solid foundations to support 
them. The foundation is generally made of solid stone work 
up to the level of the foundry floor; upon this is placed brick 
work laid in cement, or cast-iron columns or posts, for the sup- 
port of the iron bottom and cupola. In all cases where the 
cupola is set at sufficient height from the floor to admit of the 



THE CUPOLA FURNACE. 3 

use of the iron supports they are to be preferred to brick work, 
as they admit of more freedom in removing the dump and re- 
pairing the lining. The columns or posts are placed at a suffi- 
cient distance apart to permit the drop doors to swing free 
between them. This arrangement removes the liability to 
breaking the doors by striking the cupola supports in falling, 
and admits of their being put back out of the way when remov- 
ing the dump. 

The height of the bottom of the cupola above the mould- 
ing floor depends upon the size of the ladles to be filled, and 
varies from fourteen inches to five feet. If placed too high 
for the sized ladle used, considerable iron is lost by sparks and 
drops separating from the stream in falling a long distance, and 
the stream is more difficult to catch in the ladles. For hand 
ladle work it is better to place the cupola a little higher than 
fourteen inches, and rest the ladle upon a hollow oblong ped- 
estal eight or ten inches high, and open at both ends, than to 
set it upon the floor. The ladle can then be moved back or 
forward to catch the stream, and iron spilled in changing ladles 
falls inside the pedestal, and is prevented from flymg when it 
strikes the hard floor, and is collected in one mass inside the 
pedestal. This arrangement reduces the liability of burning 
the men about the feet and renders it easier to lift the full ladle. 

If a cupola is set very low, it is then necessary to make an 
excavation or pit beneath it to permit of the removal of the 
dump, and repairing of the lining. This pit is made as wide 
as it con\'eniently can be, and of a length equal to two or three 
times the diameter of the cupola. The distance from the 
bottom plate to the bottom of the pit should not be less than 
three feet. The bottom of the pit is lined with a hard quality 
of fire-brick set on edge, and the floor sloped from the edges to 
the center, and from the end under the cupola outward, so that 
any molten iron falling with the dump will flow from under 
the cupola, and thus facilitate its removal. In the center of the 
pit under the cupola a block of stone or a heavy. block of iron 
is securely placed, upon which to rest the prop for the support 
■of the iron bottom doors. 



4 THE CUPOLA FURNACE. 

The bottom plate is made of cast iron, and must be of 
sufficient thickness and properly flanged or ribbed to prevent 
breaking. If broken when in place, it can not be removed, and 
it is then almost impossible to securely bolt it so as to hold 
it in place. The plate must be firmly placed upon the iron 
supports or brick work, so that no uneven strain will be put 
upon it by the weight of the cupola and stack. 

The bottom doors are made in one piece or in two or more 
sections. For large cupolas the}' are generally made in two 
or four sections to facilitate raising them into place. They 
are made of cast or wrought iron. Those made of cast iron 
are, when in place, the stififest and firm.est. Those made of 
wrought iron are the lightest and easiest to handle, but are 
also more liable to be warped by heat in the dump, and to 
spring when in place. The door, or doors, whether made of 
cast or wrought iron, have wide flanges to overlap the bottom 
plate and each other when in place, to prevent the sand, when 
dry, running out through cracks and making holes in the sand 
bottom. The doors are supported in place by a stout iron or 
wooden prop; and when they are light, or sprung, one or 
more additional props are put in for safety. Numerous bolts' 
and latches have been devised for holding the doors in place, 
but they have all been abandoned in favor of the prop, which 
is the safest. Sliding doors, or plates, have been arranged 
upon rollers to slide into place under the cupola from the sides, 
and be withdrawn by a ratchet or windlass to dump the cupola. 
They admit of easy manipulation ; but in case of leakage of 
molten iron through the sand bottom, they are sometimes burnt 
fast to the bottom plate and cannot be withdrawn, and for this 
reason the sliding door is seldom used. 

The casings are made of cast or wrought iron plate. When 
made of cast iron they are cast in staves, which are put in place 
on the iron bottom and bound together by wrought iron bands ; 
these bands being shrunk on. Or they are cast in cylindrical 
sections, which are placed one on top of another, and bolted 
together by the flanges. This kind of casing generally cracks 



THE CUPOLA FURNACE. 5 

from expansion and shrinkage in a short time, and is the poor- 
est kind of casing. With the cast iron casing a brick stack, 
constructed upon a cast iron plate supported by four iron col- 
umns, is generally used. The wrought iron casing is more 
generally employed at the present time than that of cast iron. 
It is made of boiler plate, securely riveted together with one 
or two rows of rivets ; but one row of rivets, and those three 
inches apart, is generally found to be sufficient, as the strain 
upon the casing, when properly lined, is not very great. 

The stack casing is generally made of the same material as 
that of the cupola, and in continuation of the cupola casing; 
the two generally being made in one piece. 

The stack is made the same size as the cupola, or is con- 
tracted or enlarged according to the requirements or fancy of 
the foundryman. A contracted stack gives a good draught, 
but throws out a great many sparks at the top. An enlarged 
stack gives a poor draught, unless it is very high, but throws 
out very few sparks at the top. As sparks are very objection- 
able in some localities, and not in others, different-sized stacks 
-are used. When surrounded by high buildings or hills, the 
stack must be made of sufficient height to give the necessary 
draught for lighting up in all kinds of weather, and then vary 
in height from a few feet above the foundry roof to twenty or 
thirty feet. Bands of angle iron are sometimes riveted to the 
inside of the cupola and stack casings to support the lining, and 
admit of sections being taken out and replaced without remov- 
ing the entire lining. 

The casing and lining are perforated with two or more tuyere 
holes near the bottom, for the admission of air by draught or 
forced blast. These tuyeres, when supplied with a forced 
blast, are connected with the blower by branch pipes to each 
tuyere, or are supplied from an air chamber riveted to the 
■cupola casing either on the outside or inside. The air chamber 
is made three or four times the area of the blast pipe, and is sup- 
plied fron^ the blast pipe connecting it with the blower. An 
-opening is made through the casing and lining, just above the 



O THE CUPOLA FURNACE. 

bottom plate, for drawing the molten iron from the cupola, and 
a short spout is provided for running it into the ladles. An- 
other small opening is sometimes made, just under the lower 
level of the tuyeres, for tapping or drawing off the slag from 
the cupola. This opening is never used except when a large 
amount of iron is melted, and the cupola is kept in blast for a 
number of hours. 

An opening for feeding the furnace, known as the charging 
door, is placed in the cupola at a height varying from six to 
twenty feet above the bottom plate, according to the diameter 
of the cupola. This opening is sometimes provided with a 
cast iron frame or casing on the inside to protect the lining 
around the door when putting in the fuel and iron. A door 
frame is placed upon the outside, upon which are cast lugs for a 
swinging door, or grooves for a sliding door. The door for 
closing the charging aperture may consist of a cast or wrought 
iron frame filled with fire-brick, or be made of boiler plate with 
a deep flange all around for holding fire-brick or other refrac- 
tory material. The sliding door consists of an iron frame 
filled in with fire-brick, and is hung by the top, and moved up. 
and down with a lever or balance weights. This door is moved 
up and down in grooves cast upon the door frames, which 
grooves frequently get warped by the heat, and hold the door 
fast. The hinge or swing door, with plenty of room for expan- 
sion and shrinkage, is the door generally used. 

The casing is lined from the bottom plate to the top of the 
stack with a refractory material. A soft refractory fire-brick, 
laid up with a grout composed of fire-clay and sand, is used for 
lining in localities where such material can be obtained. In 
localities where fire-brick can not be procured, soapstone from 
quarries or the bottoms of small creeks, is laid up with a re- 
fractory clay. Some grades of sandstone or other refractory 
substance are also employed for lining. Native refractory 
materials are seldom homogeneous, and those which have been 
ground and moulded, or pressed into blocks, make the best lin- 
ings. The thickness of the lining varies in large and smalt 



THl': CUPOLA FURNACE. 7 

cupolas. Those in the large cupolas are from six to nine 
inches, and in small cupolas from four to six inches. 

The charging aperture being placed at too great a height 
from the floor to admit of the cupola being charged or loaded 
from the floor, a scaffold or platform is erected from which 
to charge it. The scaffold is generally placed in the rear of 
the cupola, so as to be out of the way when removing the 
molten iron in crane ladles. But for hand-ladle work it is placed 
at any point most convenient for getting up the stock, and the 
charging aperture placed in the cupola at any point most con- 
venient for charging. For very large cupolas the scaffold is 
frequently constructed to extend all around the cupola, and a 
charging aperture is placed in the latter on each side, so that it 
may be more rapidly charged. The scaffold is constructed 
of wood or iron frame work, or is supported by a brick wall. 
The floor is placed level with the bottom of the charging 
aperture, or is placed from one or two feet below it. The scaf- 
fold should be made large enough to place a weighing scale 
in front of the charging door, to hold iron and fuel for several 
heats, and have plenty of room for handling the stock when 
stocking the scaffold and charging the cupola. Nine-tenths of 
the scaffolds are too small for the work to be done on them, 
and the cupola men work to a great disadvantage when hand- 
ling the stock. Much of the bad melting done in foundries 
can be traced directly to the lack of room on the scaffold for 
properly charging the cupola. 



CHAPTER II. 

IMPROVEMENTS IN CUPOLAS. 

From the best information obtainable, it appears that the 
first cupola furnaces used in foundries in this country were of 
the type of the stationary bottom draw front cupola. These 
were constructed upon a solid stone or brick foundation from 
three to four feet high, or upon a hollow foundation with a cast 
iron plate on top, upon which a cupola bottom of fire-brick or 
other refractory material was placed. 

The cupola castings were generally made of cast iron, with 
the front opening of a sufificient size to admit of the refuse from 
melting being drawn from the cupola through the front with an 
iron hook or rake. 

The lining was arched over the front and the opening closed 
with an iron plate or apron, which was put in place when the 
lining and bottom had been repaired and made ready for a heat 
and securely fastened with hooks or other devices. To protect 
the apron, a temporary lining was put in of loam or other 
material that could be readily removed while hot after the heat 
was melted. 

When the cupola was large the apron was put in place and 
the temporary lining put in before the fire was lighted, and 
in small ones a wall of coke was built up in the opening, and 
the loam or other material rammed into the front after the fire 
was burned up, and the apron placed over it. A small open- 
ing or front was placed in the apron for the tap hole. 

This style of cupola was the only one used in this country 
for many years, but it has now generally been replaced by more 
modern ones. Probably three of the most perfectly con- 
structed cupolas of this design ever built in this country were 

(8) 



IMPROVEMENTS IN CUPOLAS. 9 

those in the foundry plant of Chas. Reeder & Sons, Baltimore, 
Md. These cupolas were inconstant use until about two years 
ago when the plant was abandoned and torn down. These 
works were established in 1813 for the manufacture of marine 
and stationary engines, and some of the largest and most pow- 
erful marine and stationary engines constructed in early days 
were cast at this foundry. 

To melt iron for these castings, three draw-front cupolas 
were constructed upon the latest improved pattern of the 
times; the exact date at which they were built is not known, 
but it must have been many years ago, for the old foreman in 
1874 informed me they were used in melting the iron for cast- 
ings of marine engines placed in well-known vessels, that had long 
been out of existence at that time. The cupolas at the time 
of my last visit to the works, some years ago, were the only ones 
in the foundry, having held their own against all the changes in 
fashion, until they became the leaders of fashion, for the draw 
front has again come in use to a considerable extent during the 
past few years for very small cupolas. These cupolas, three in 
number, were placed in a row close together upon a cast iron 
plate supported by a brick foundation three feet high. 

Upon this plate eight cast iron columns ten feet high were 
placed, for the support of the stack plate upon which rested 
the cupola stack. The casings of the cupolas and stack were 
made of boiler plate, the stack was placed directly over the 
center cupola with side wings extending over the others on 
•either side, so that one stack served for the three cupolas, which 
were of dititerent sizes. The smallest one was straight and 20 
inches in diameter inside the lining. The other two were taper- 
ing from bottom to top, one with a diameter inside lining of 42 
inches at tuyeres, 36 inches at top, and the other 48 inches at 
tuyeres and 40 inches at top. 

The tuyeres were square and placed 16 inches above bottom. 
The larger cupolas had four tuyeres and the small one two. 
The cupola castings were all of the same height, measuring ten 
ieet between bottom and top plate, but the charging door, 24 



lO THE CUPOLA FURNACE. 

inches high, was phiced in each cupola below the top plate, 
which reduced their height to 7^ or 8 feet. 

The cupola scaffold was very small, having scarcely sufficient 
room for stock for the small cupola. This appears to have 
been the general way of constructing scaffolds in early days, 
the practice being to only place stock upon the scaffold as it 
was required for charging, one man placing it in the cupolas as 
fast as one or more men threw it upon the scaffold from the 
stage or platform upon which fuel and iron were thrown in 
passing it up from the yard to the scaffold. There do not 
appear to have been any cupola runways or elevators in " our 
grandfathers' day." One of these cupolas, I was informed, was 
changed to a drop bottom about the time the drop bottom first 
came into use, but after the loss of a number of heats, from the 
support of the bottom giving way or leakage through the sand 
bottom, it was changed back to a stationary bottom, which was 
considered safer than the drop. 

These cupolas did good work in a number of heats I saw 
melted in them ; in fact, they melted equally as well as any of 
the more modern cupolas of the same diameter and height, of 
which there were a great many in use at the time referred to. 

But the refuse from melting was not so easily removed as 
from the more modern cupolas. When the apron was removed 
and the front broken away, the refuse under the tuyeres was 
readily drawn out, but after this was removed cold air was ad- 
mitted, which chilled the slag and cinder over the tuyeres, ren- 
dering it tough and difficult of removal, and when the cupola 
was slightly bridged and the refuse did not drop freely, it was 
almost impossible to remove it. This difficulty occurred so 
frequently that a long bar was kept on the scaffold for poking 
the refuse down and getting a hole through, that it might cool 
off by the next morning. 

This is the great objection to the draw-froht cupola, which is 
overcome to a considerable extent by the drop-bottom, which 
gives way the instant the support is removed and permits every- 
thing to drop out when the cupola is not bridged, before it has 
time to become chilled and tough. 



IMPROVEMENTS IN CUl'OLAS. II 

Melters who have never melted in a large stationary bottom 
cupola have little idea of what a great boon this w as to melters, 
in the early days, when the tapping of slag from cupolas was 
not thought of, and it was a common thing to work one or' more 
hours to get a hole through after each heat. 

The drop bottom is said to be an American invention and to 
have been first used in the New England States, but there ap- 
pears to have been no record of the date at which it was first 
used, and the oldest foundrymen I have met have not been able 
to give the date at which it was first introduced. 

But so far as I have been able to learn, it has been in use at 
least fifty years, and perhaps longer, but it was not adopted by 
all founders when it was first introduced, and many of the sta- 
tionary bottom cupolas of the old pattern were in use at a much 
later date, and may still be in use in some of the old foundries 
like the one before referred to. 

With the introduction of the drop bottom cupola there does 
not appear to have been any other change made in the con- 
struction of cupolas. They were generally built upon a brick 
or stone foundation, with square cast-iron bottom plates, upon 
the corners of which were placed four columns for the support 
of another plate upon which was constructed a square stack of 
common red brick. 

The stacks were generally made of a much larger area than 
the cupolas, that the red brick of which they were constructed 
might not be burned out and also to prevent sparks or hot 
cinders being thrown out at the top of the stack. The charg- 
ing door was generally placed in the stack just above the plate_ 

Cupola castings were generally made of cast iron and were 
cast in staves the length or height of the cupola and from four 
to six inches \\ide. These staves rested upon the bottom plate 
and projected up through an opening in the stack plate several 
inches, or came even with the top of it, and were held together 
by wrought-iron bands placed a foot or more apart. When 
boiler plate was obtainable and it was desired to have some- 
thing fine, castings were made of this material, but the cast-iron 



12 THE CUPOLA FURNACE. 

Stave casings were more common. Small cupolas were gener- 
ally made straight and large ones tapering, with the larger end 
down to facilitate dumping, and their height was from six to 
eight feet, eight feet being considered a very high cupola. 

Blast was supplied through two tuyeres, one placed on either 
side of the cupolas, and opposite each other, so that blast from 
each met in the center. When only light work was to be cast 
they were placed twelve to eighteen inches above the bottom ; 
for heavy work, three sets of tuyeres, one above the other, were 
put in. They were generally placed twelve, eighteen and 
twenty- four inches above the bottom. These tuyeres were 
designed for melting iron for a heavy casting, and when such 
a piece was to be cast, blast was first put in through the lower 
ones until the cupola was filled with molten iron to this point. 
They were then closed with clay and the next set opened, and 
blast put in until molten iron appeared, when they were closed 
and the next set opened. To admit of blast being adjusted to 
the tuyeres of dififerent heights, a tuyere pipe or nozzle of tin or 
copper was provided and attached to the blast pipe by a leather 
tube, one end of which was slipped over the blast pipe and the 
other over the end of the nozzle and securely tied with a leather 
thong or lace. 

A hole was placed in the bend of the nozzle or elbow and 
closed with a wooden plug for watching the filling up of the 
cupola with molten iron, and also for poking the tuyeres when 
they became black. 

To admit of the blast being adjusted to the different height 
of tuyeres when the cupola was in blast, the iron and fuel were 
not placed in charges, but were mixed by putting in a shovel 
or two of fuel and a hundredweight or two of iron. This was 
the common practice of filling the cupola. 

This plan of melting for heavy castings did not prove very 
satisfactory, and later on, in cupolas designed for heavy work, 
but one set of tuyeres was put in, and these located 24 inches 
above the bottom ; these gave better results than the adjustable 
tuyeres. 



IMPROVEMENTS IN CUPOLAS. 13 

Tuyeres were mostly made very small for the purpose of 
putting in the blast with great force, and driving it to the center 
of the cupola, and were generally made from 3 to 5 inches in 
diameter, according to the diameter of the cupola. Two of 
these small tuyeres were considered ample for a small cupola 
and four for a large one. 

These old-fashioned cupolas, in many of which I have melted 
iron, generally melted very slow. This was due to the tuyere 
area being entirel)' too small to supply a sufificient volume of 
blast and to the cupolas being too low to utilize all the heat of 
the fuel for heating the iron and preparing it for melting, before 
settling into the melting zone. 

With a cupola only seven feet high, tuyeres 24 inches above 
the bottom, and top of bed 18 to 20 inches above tuyeres, only 
3 to 33^ feet was left for fuel and iron above the bed. It is 
obvious to almost any founder nowadays, that this was not 
sufficient space in which to utilize all the heat of the fuel ; but 
this was not the case some years ago, and when I published my 
first work on foundry practice in 1877, in which I placed a table 
for heights of cupolas, ranging from 6 to 15 feet, according to 
diameter of cupolas. This table was ridiculed by the majority 
of foundrymen, and a 15-foot cupola was declared by many to 
be impracticable ; but the heights given in this table have all 
been reached and in many cases passed, and the tendency at 
the present time is to go to the other extreme and overreach 
the height at which the heat that can be utilized is sufficient to 
pay for the extra expense of cupola, lining, elevating stock, etc. 

There are a few of these old-fashioned brick stack cupolas 
still in use. There is at least one in Philadelphia, Pa., and two 
or three could probably be located in Brooklyn, N. Y., and a 
few in other places, but they have generally given place to the 
more modern cupolas. 

There does not appear to have been any improvement made 
in cupolas for many years after the adoption of the drop bot- 
tom, and they were all constructed with stave casings, brick 
stacks, etc. The next advancement was the use of boiler- plate 



14 THE CUPOLA FURNACE. 

casings for both cupola and stack, and construction of cupola 
and stack in one piece, doing away with the cast-iron staves, 
columns, stack plates and brick stacks. 

Following this came the abandonment of the adjustable 
tuyere, nozzle, leather tube, etc., the enlargement of tuyeres, 
use of variously shaped tuyeres, attachment of blast pipes to 
cupolas, introduction of tuyere boxes, air chambers, etc. ; any 
and all of which were a great improvement over the tuyere 
nozzle and leather tube, which frequently permitted as great an 
amount of blast to escape as passed into the cupola. About 
this time the taper was also abandoned and cupolas of all sizes 
made of the same diameter from bottom to top. 

With the increase in size of tuyeres, and more perfect con- 
nection of blast pipes with cupolas, it became apparent from 
the amount of heat at the charging door that cupolas were too 
low, and their height was increased from time to time, until 
heat no longer appeared at the charging door sufficient to burn 
the hand when the cupola was filled with slock and in full blast. 

The next improvement was the lowering of the tuyeres from 
12, 18 and 24 inches above the bottom to from 4 to 10 inches 
above the bottom, and in many of the large cupolas they were 
placed so low that the sand bottom came up to the bottom of 
the tuyeres at back of cupola. 

These changes were all effected in the common straight 
cupola, and brought it to such a perfection as a melter of iron 
many years ago that it is very doubtful if any improvement has 
been effected in cupolas since that time. 

Before these improvements were made cupolas melted very 
slow, and it was the practice to put on the blast just after the 
noon hour and melt all afternoon. From four to five hours 
were commonly required to melt any ordinary heat. 

Holders generally stopped molding when the blast was put 
on, and a great deal of valuable time was lost waiting for iron. 
To prevent this loss of time, Mr. Mackenzie, a practical molder 
and founder of Newark. N. J., conceived the idea of melting a 
heat in two hours, and designed the Mackenzie cupola, which, 
when first introduced, was known as the two-hour cupola. 



IMl'ROVEMENTS IN CUPOLAS. 1 5 

This cupola, I believe, was the first cupola patented in this 
country, and it presented a number of new features in cupola 
construction. 

The old theory of driving blasts to the center of the cupola 
by force of the blower and the small tuyeres was entirely 
abandoned, and the theory of supplying a sufficient volume of 
blast to fill the cupola adopted. Cast-iron tuyere boxes were 
bolted to the castings for the attachment of blast pipes, and 
blast was delivered to the cupola from an inside belt air 
chamber and continuous tuyere. The air chamber which was 
formed by an apron riveted at the top to the cupola shell was 
entirely open at the bottom, giving unlimited space for escape 
of blast into the cupola. 

This was a complete change from the old theory of putting 
blast into a cupola with great force, and revolutionized the 
theory of melting. This cupola gave excellent results, and was 
adopted by all the leading foundrymen of the time, and many 
of them are still in use. and continue to give good results in 
melting wlien properly managed. 

But this cupola has its objectionable features, the greatest of 
which is its tendency to bridge and bung up when not properl}' 
managed. This tendency to bridge is due to a large extent to 
the cupola being boshed by the inside air chamber, and the 
blast being supplied to it just at the point of the lower angle of 
the bosh. The blast passes up over the bosh before it becomes 
heated, causing a chilling of cinder and slag at this point, and 
the building-out of the lining with a very hard substance 
that is difficult to remove, and careless or incompetent melters 
frequently permit the lining to grow at this point until the 
melting capacity of the cupola is reduced one-half, and the 
smaller ones frequently bridge before they are in blast more 
than an hour when the lining is permitted to get out of shape. 

Much better results might have been obtained from this 
cupola had the inventor furnished, to be hung up near the 
cupola for the guidance of the melter, a framed diagram or 
blueprint, showing the proper shape for lining of the bosh and 



1 6 THE CUPOLA FURNACE. 

melting zone when the hning was new and as it burned away; 
but such a diagram was never furnished, and I have frequently 
seen melters running these cupolas who did not have the least 
idea of the shape the lining should be put in when repairing it 
for a heat, having never seen one when newly lined or in shape. 

The next patent cupola to come into prominence was the 
Truesdale cupola, designed by Mr. Truesdale, foreman of the 
Resor Stove Works, Cincinnati, Ohio. This cupola was sup- 
plied with blast from an inside belt air chamber through the 
Truesdale reducing tuyere, which consisted of a series of open- 
ings through the lining placed one above the other only an 
inch or two apart, the diameter of each reduced half an inch 
from the one directly under it. 

The lower tuyere was from 3 to 4 inches in diameter, accord- 
ing to diameter of cupola, and the top one, one inch in diam- 
eter. A sufficient number of these tuyeres were placed in a 
cupola to admit a proper volume of blast for melting ; the object 
of these tuyeres being to distribute the blast to different parts 
of the bed in a sufficient volume to produce a rapid and thor- 
ough combustion of the fuel. This arrangement gave excellent 
results in cupolas of large diameter, but was not so satisfactory 
in small cupolas, as the tendency to bridge was increased by 
the inside air chamber and arrangement of tuyeres. 

The cupola was designed for melting with coke only, and its 
use was restricted to the West, the greater number of them being 
used in Cincinnati and vicinity, where some are probably still 
in use, but most of them have been replaced by more modern 
cupolas. 

The next patent cupola to come into prominence was the 
Lawrence cupola, designed and patented by Mr. Frank Law- 
rence, foreman of the American Stove and Hollow Ware Co., 
Philadelphia, Pa. 

This cupola was designed for melting with coal or coke, and 
was quite extensively used both in this country and Canada. 
Its principal feature was a reducing tuyere, consisting of an 
opening 3 or 4 inches square, directly over which was. an up- 



IMPROVEMENTS IN CUPOLAS. I 7 

li^ht slot opening 10 to 12 inches long and i to i ^ inches 
wide at the bottom, and tapering to a point at the top. These 
tuN'eres, like the Truesdale, were su[)plied with air from an 
inside air chamber, and were designed to distribute the blast to 
produce a more rapid and thorough combustion than when all 
the blast was admitted at the same level. The cupola was gen- 
erally boshed and the casings of the larger ones were enlarged 
in the center, giving them an egg shape between the top of the 
tuyeres and bottom of the stack, the charging door being 
placed in the stack. The cupola, when of good size, was the 
most rapid melter with coal ever designed, and was quite 
extensively used with this fuel. 

Another cupola that attracted some attention was the Pcvie 
cupola, designed by Mr. Pevie, a practical foundryman of a 
small town in Maine. This cupola was an oblong or fiat one 
from 20 to 30 inches wide and from 4 to 6 feet long. Bla^t 
was admitted to it through a horizontal slot tuyere placed on 
each side and extending the full length of the cupola. The 
(object of this construction was to force blast to the ceater of 
the cupola and produce even melting, which it no doubt did. 
But the tendency of the cupola to bridge was so great that it 
never came into general use. only a few of them being placed 
in foundries. Of these I have seen only four, one of which was 
in Mr. Pevie's own foundry, and judging from the number of 
cupola salamanders lying around, the inventor had not himself 
been able to overcome the tendency of the cupola to bridge. 

Another cupola, or rather tuyere, which came into promi- 
nence in Philadelphia and vicinity was " The Dougherty," 
designed by Mr. Dougherty, of the firm of Dement and Dough- 
erty. This improvement consisted in placing tuyeres in a 
cupola in such a manner as to give to the blast a circling or 
swirling motion around the cupola through the stock, in place 
of passing straight in and up through the stock. This arrange- 
ment for some time was considered to improve the melting, and 
many of these tuyeres were placed in cupolas ; but after a thor- 
ough test there proved to be nothing in this motion given to 
2 



I 8 THE CUPOLA FURNACE. 

the blast, and, like many other improvements, the tuyere was 
abandoned. 

All of these cupolas that, met with any success, depended 
for this upon the shape of the lining or arrangement of the 
tuyeres, and when these were maintained as originally designed 
good results in melting were obtained. But when placed in 
the hands of the average melter these conditions were ignored. 
Linings were permitted to get out of shape, tuyeres closed 
up or collapsed, directions for melting were not followed, and 
the cupola sooner or later in a vast majority of cases proved a 
complete failure and was changed to a plain cupola or replaced 
with the old-fashioned straight, lound cupola, which demon- 
strates that fancy shapes in linings or the distribution of blast 
to the bed through numerous small or fancy shaped tuyeres, 
is not practical in cupola practice, and sooner or later proves a 
complete failure. 

Following these fancy-shaped and numerous-tuyered cupolas 
came the " Colliau " plain round cupola, designed by Mr. 
Colliau, and first introduced about 1874 or 75. This cupola 
was designed to be a fast and economical melter as well as a 
continuous melter But when first introduced it proved such a 
complete failure that Mr. Colliau's financial partner committed 
suicide, and Mr. Colliau himself was on the verge of bankruptcy ; 
but he persevered, and after numerous changes finally suc- 
ceeded in making it the leading cupola of his, and of the 
present, time. 

The cupola, when first introduced, presented a number of 
new features in construction and management, among which 
were a hot blast, a double row of tuyeres, the tapping of slag, etc. 

The hot blast was to be produced by extending the air 
chamber from the bottom of the cupola up to near the charg- 
ing door, on the outside, and heating the blast with heat escap- 
ing through the cupola shell. The heat escaping through the 
shell was found to be insufficient to heat the blast, and this 
feature was a complete failure, and after constructing a few 
cupolas on this plan it was abandoned as impracticable. Had 



IMPROVEMENTS IN CUPOLAS. 1 9 

Mr. Colliau applied this theory to some of the old-fashioned 
stave cupolas, in place of a tight boiler-plate casing, he might 
have met with more success, and he probably got his idea from 
these cupolas, for I have seen sufficient heat escape from them 
to at least warm a blast, if not heat it, by surrounding the en- 
tire cupola with a belt air chamber and passing the blast 
through it before entering the cupola through the small tuyeres 
then in use. The double rows of tuyeres were also a failure 
when first introduced, and it was found to be almost impossible 
to make hot iron with double the amount of fuel required for a 
bed to make hot iron with a single row of tuyeres, and the use 
of the cupola was restricted to foundries making heavy work 
and not requiring very hot iron. 

This objectionable feature was finally overcome by reducing 
the size of the upper row and placing them nearer to the lower 
row or lower in the cupola. The tapping of slag and the con- 
tinuous melting was a success from the beginning, and this was 
all that saved the cupola from a complete failure. 

The tapping of slag from blast furnaces had long been in 
vogue in this country, but Mr. Colliau was the first to apply 
this system of melting to cupolas, and it proved a decided ad- 
vantage in long heats, for prior to its introduction it was almost 
impossible to run a small cupola for a greater length of time 
than two hours, or a large one for more than four, and do good 
melting. 

Mr. Colliau also changed the form of cupola supports, bot- 
tom doors, air chambers, adopted a scale of heights for cupolas 
of different diameters, and probably did more to advance cupola 
construction in this country than any other cupola designer. 

His designs both before and after his death were adopted by 
other cupola manufacturers, and the general construction of 
cupolas at the present time is upon the Colliau plan. 

The double row of tuyeres was not original with Mr. Colliau. 
They had been used in France, prior to his introduction of 
them in this country, and the Truesdale and Lawrence tuyeres 
were practically on the same principle, applied in a little differ- 



20 TITE CUPOLA FURNACE. 

cnt form, but the Colliau arrangement was not so apt to close 
up and get out of order, and was more practical, and has come 
into general use. 

The utility of these tuyeres depends to a large extent upon 
the conditions under which 'hey are used. They require a 
higher bed and are more destructive to lining material than the 
single row of tu}-eres, and in foundries employing a small num- 
ber of moulders and running short heats they arc an expensivr 
luxury. 

The manufacturers of cupolas have realized this fact and 
arranged a device for closing the top row when large heats for 
the size of cupola are not to be melted, and in fully nine-tenths 
of these cupolas in use, I find the second row cither perma- 
nently or temporarily closed, which places the cupola in the 
same condition as the improved cupola of " 40 years ago." 

The double row mchs iron more rapidly than the single rt)w 
in cupolas of the same diameter, and a third and fourth row 
have been added to advantage in this res[)ect when properly 
arranged. But the destruction of lining material from the use; 
of these numerous tuyeres is very heavy and the amount of 
fuel required is greatly increased. 

In foundries employing a large number of molders and melt- 
ing heavy heats, rapid melting increases the output of the 
foundry to a considerable e.xtent by allowing more time for 
molding work, and these numerous tuyere cupolas are being 
used with good results in foundries of this class ; the heavy de- 
struction of lining material and increased expenses of melting 
being more than overcome by the increased output of tlic 
foundry. 

It is therefore a matter for every founder to decide whether 
it is more economical to melt fast or slow, the actual cost df 
cupola lining, etc., being a secondary consideration when offset 
by other conditions. 

I might describe numerous other cupolas I have seen in 
operation, but those just described embrace all the principles 
embodied in other new designs of cupolas and arrangement of 



IMPROVEMENTS IN CUPOLAS. 2 1 

tuyeres, nearly all of which have gone out of use or are being 
used only to save expense of replacing them with other cupolas. 

After all the supposed improvements we have practically 
come back to the plain round cupola of 40 years ago, with 
practically no improvements, save the enlargement of tuyeres 
and increase in height of cupola. These improvements have 
made the common round cupola superior to any other for gen- 
eral foundry use, and with the improvement made in blast 
machinery enormous quantities of iron may be melted in it in a 
very short time with the single-row tuyere cupola, and with the 
double and triple tuyere arrangement more iron may be melted 
per hour than the output of our most improved blast furnaces 
for the same length of time. 

The common round cupolas with the single or double row 
of tuyeres, as desired, are now manufactured by numerous 
cupola manufacturers located in different parts of the country, 
and founders who contemplate putting in new cupolas will 
probably find it cheaper to order a cupola with such changes 
in its construction as they may desire than to go to the expense 
of making patterns and constructing their own cupola. 



CHAPTER III. 

CONSTRUCTING A CUPOLA. 

When about to construct a cupola to melt iron for foundry- 
work, the first thing to be decided on is the proper location. In 
deciding this a number of points are to be taken into consider- 
ation, the two most important of which are the getting of the 
stock to the cupola and the takmg away of the molten iron. It 
should be borne in mind that there is more material to be 
taken to a cupola than is to be taken away from it. F^or this 
reason the cupola should be located as convenient to the stock 
as possible. It must also be borne in mind that the object in 
constructing a cupola is to obtain fluid molten iron for the work 
to be cast, and if the cupola is located at so great a distance 
from the moulding floors that the molten metal loses its fluidity 
before it can be poured into the mould, the cupola fails in the 
purpose for which it was constructed. 

If the work to be cast is heavy and the greater part of the 
molten metal is handled by traveling or swinging cranes, the 
small work may be placed near the cupola and the cupola 
located at one side or end of the foundry near the yard. But 
if the work is all light hand-ladle or small bull-ladle work, the 
cupola should be located near the center of the moulding room 
so that the molten iron may be rapidly conveyed to the moulds 
in all parts of the room. 

SCAFFOLD. 

It is often found diflficult, owing to the shape of the mould- 
ing room and location of the yard, to place the cupola conve- 
niently for getting the stock to it and the molten iron away from 
it. When this is the case, means must be provided for getting 
the stock to the cupola and the cupola located at a point from 

(22) 



CONSTRUCTING A CUPOLA. 23 

which the molten metal can be rapidly conveyed to the moulds. 
At the present low price of wrought iron and steel, a fire proof 
cupola scaffold can be constructed at a very moderate cost, and 
the difftculty of locating the cupola convenient to the yard may 
be overcome by constructing a scafifold of a sufficient size to 
take the place of a yard for iron and fuel. The scaffold may 
be constructed under the foundry roof and made of proper 
size to hold one or two cars of coal or coke, a hundred tons of 
pig and scrap iron and all the necessary material for a cupola. 
The space under the scaffold can be utilized as moulding floors 
for light work or for core benches, core oven, ladle oven, sand- 
bins, etc. The cupola and its supplies are then under roof, 
and there is no trouble from cupola men staying at home in 
bad weather, as is often the case when the cupola and stock 
are out of doors. 

When this arrangement is adopted, an endless chain or 
bucket elevator should be constructed to convey the coal or 
coke to the scaffold as fast as it is shoveled from the truck 
or car. Another elevator should be provided for pig and scrap 
iron, and as the iron is thrown from the car it is broken and at 
once placed upon the scaffold convenient for melting. This 
arrangement saves considerable expense for labor in the rehand- 
ling of iron and fuel, and also prevents the loss of a large amount 
of iron and fuel annually tramped into the mud in the yard and 
lost. The saving in labor and stock in a short time will pay the 
extra expense incurred in constructing this kind of scaffold. 

CUPOLA FOUNDATION. 

Too much care cannot be taken in putting in a cupola foun- 
dation, for the weight of a cupola and stack, when lined with 
fire-brick to the top, amounts to many tons, and when loaded 
with fuel and iron for a heat to many tons more. If the foun- 
dation gives way and the cast-iron cupola bottom is broken by 
uneven settling, the cupola is rendered practically worthless, 
for it is impossible to replace the bottom with a new one with- 
out taking out the entire lining, which entails much expense, 



24 THE CUPOLA FURNACE. 

and it is almost impossible to bolt or brace the plate so as to 
keep it in place. 

The foundation should be built of solid stone work, and if a 
^ood foundation cannot be had, piles must be driven. Separate 
stone piers should never be built for each column or post, for 
they frequently settle unevenly and crack the bottom plate. 
Uneven settling and breaking oi the bottom are, to a large ex- 
tent, prevented by placing a heavy cast iron ring upon thi- 
stone work upon which to set the cupola supports. This ring 
should be placed several inches below the fioor to prevent it 
being warped and broken by the heat in the dump. 

When brick walls are constructed for the support of a cupola, 
the bottom plate is made square, from two to three inches 
thick and strongly ribbed or supported by railroad iron be- 
tween the walls, to prevent breaking. The walls do not admit 
of sufficient freedom in removing the dump and for this reason 
are, at the present time, seldom used in the construction of 
cupolas. Even when the cupola is set so low that a pit is re- 
quired for the removal of the dump, the iron supports are used 
and the pit walls built outside of them. When the round cast 
iron columns are employed, the plate must be made square or 
with a projection for each column, to admit of the columns being 
placed at a sufficient distance apart to let the bottom doors 
swing between them. The best supports for a cupola are the 
T-shaped posts. They take up less room under the cupola and 
are less in the way when removing the dump than the round 
columns, and when slightly curved at the top can be placed at 
a sufficient distance apart to permit of the drop doors swinging 
between them. When these posts are used, the bottom j^late 
is made round and of only a slightly larger diameter than the 
cupola shell or air chamber, and wdien made of good iron and 
the foundation plate is used, the bottom plate does not require 
to be more than i ^ or 2 inches thick for the largest sized 
cupola. The supports when curved at the top must be bolted 
to the plate to hold them in place. 



CONSTRUCTING A CUPOLA. 



-3 



HEIGHT OF CUPOLA BOTTOM. 

The height the bottom of a cupola or spout should be placed 
above the moulding floor or gangway depends upon the class 
of work to be cast. For small hand-ladle work the proper 
height is i8 to 20 inches; for small bull- and hand-ladle work 
24 to 30 inches; and for large crane-ladle work three to five 
feet. 

It is very difficult and dangerous to change ladles and catch 
a large stream from a higl'i cupola in hand-ladles ; and when 
pieces are only cast occasionally, requiring the use of a large 
crane-ladle, it is better to place the cupola low and dig a pit in 
front of it, in which to set the ladle when a large one is re- 
quired for the work. 

When the cupola is set low, room must be made for the re- 
moval of the dump. This may be done by constructing a wall 
in front of the cupola to keep up the floor under the spout, and 
lowering the floor under and around the back part of the 
cupola. When the cupola is so situated that this can not be 
clone, a pit should be constructed for the removal of the dump. 

BOTTOM DOORS. 

Ft)r cupolas of small diameter, but one bottom drop door is 
used. But when the cupola is of large diameter, the door, if 
made in one piece, would be so large that there would not be 
room for it to swing clear of the foundation without setting the 
cupola too high, and the door would be very heavy and difficult 
to raise into place. For large cupolas the door is cut in the 
middle and one-half hung to the bottom on each side. Four 
and six doors are sometimes used, but they are always in the 
way when taking out the dump, and require more care in 
putting in place and supporting. 

The doors are generally made of cast iron, and vary in 
thickness from a half inch to an inch and a half, and are fre- 
quently very heavy and difficult to raise into place. If the 
doors are large they are much lighter and easier to handle 
when made of wrought iron, and if properly braced answer the 



26 THE CUPOLA FURNACE. 

purpose equally as well as the stififer cast iron ones. If the 
lugs on the bottom plate are set well back from the openings 
and the lugs on the doors made long, the doors drop further 
away from the heat of the dump, and may be swung back and 
propped up out of the way when removing the dump. 

DEVICES FOR KAISING IHE BOIT(JM DOORS. 

A number of devices have been used for raising the bottom 
doors of cupolas into place, and thus avoiding the trouble and 
labor of raising them by hand. One of the oldest of these de- 
vices is a long bar, one end of which is bolted to the under side 
of the door; on the other end is cast a weight or ball almost 
sufficient to balance the door upon its hinges when raised. 
When the door is down the bar stands up alongside of the 
cupola, and when it is desired to raise the door the bar and 
weight are swung downward. As the weight descends the 
door is balanced upon its hinges and swings up into place^ 
where it is supported by a prop or other support. This device, 
when properl)' arranged and in good order, raises the door 
very easily and quickly into place, but it is continually getting 
out of order. The sudden dropping of the door in dumping 
and the consequent sudden upward jerk given to the heavy 
weight on the end of the bar frequently breaks the bar near the 
end attached to the door, or breaks the bolts by which the bar 
is attached to the door, and the door is sometimes broken by 
the bar. For these reasons this device is very little used. 

Another device, and probably the best one for raising heav\- 
doors, is to cast large lugs with a large hole in them, on the 
bottom and the door, and put in an inch and a half shaft of 
a sufficient length to have one end extend out a few inches 
beyon<J the edge of the bottom plate. The door is keyed 
fast upon the shaft, and the shaft turns in the lugs upon the 
bottom when the door is raised or dropped. An arm or crank 
is placed upon the end of the shaft, pointing in the same 
direction from the shaft as the door. When the door is down 
the arm hangs down alongside of the iron post or column 



CONSTRUCTING A CUPOLA. 2 J 

supporting the cupola and is out of the way in removing the 
dump, and when the door is up the arm is up alongside of the 
bottom plate, out of the way of putting in the bottom props. 
The door is raised by a pair of endless chain pulley blocks at- 
tached to the under side of the scafTold floor at the top and the 
end of the arm at the bottom, and it is only necessary to draw 
up the arm with the chain to raise the door into place. This 
is one of the best devices we have seen for raising heavy doors. 
Another one, equally good for small doors and less expensive, 
is to make the end of the shaft square and raise the door by 
hand with a bar or wrench five or six feet long, placed upon 
the end of the shaft. The bar is placed upon the shaft in an 
upright position, and by drawing down the end of the bar the 
door is swung up into place by the rotation of the shaft on to 
which it is keyed. When the door is in place the bar is re- 
moved from the end of the shaft, and is not at all in the way of 
handling the iron or managing the cupola. 

CASING. 

The casing or shell of the modern cupola and stack is made 
of iron or steel boiler plate, riveted together with one or two 
rows of rivets at each seam. The thickness of the plate required 
depends upon the diameter and height of the cupola and stack. 
The lining in the stack is seldom renewed, while the lining in 
the cupola is often removed every few months and replaced 
with a new one, and the casing must be of a sufficient thickness 
to support the stack and lining when the cupola lining is re- 
moved. The strain upon the casing due to expansion and 
shrinkage is not very great when properly lined ; but when im- 
properly lined with a poor quality of fire-brick, the expansion 
may be so great as to tear apart the strongest kind of casing. 
The only way to prevent this is to take care in selecting the 
fire-brick and in laying up the lining. The greatest wear and 
tendency to rust are in the bottom sheet, and it is also weakened 
by cutting in the front, tuyere and slag holes, and should be 
made of heavier iron than any other part of the casing. Plate 



28 THE CUPOLA FURNACE. 

of 3^ inch or 3,8 inch thickness is heav}- enough for almost any 
sized cupola. The cupola and stack casing are generally made 
in one piece, the cupola ending at the charging door and the 
stack beginning at the same point. The stack may be con- 
tracted above or below the charging door, and made of smaller 
diameter than the cupola. This gives a better draught and 
••equires less material for casing and lining; but it also in 
creases the number of sparks thrown from the cupola when in 
blast. Where sparks are very objectionable, as in closely built 
up neighborhoods, it is better to make the cupola and stack of 
the same diameter, or to enlarge the stack from the bottom of 
the charging door. This may be done by placing a cast iron 
ring upon the top of the cupola shell, and supporting it b\- 
brackets riveted to the shell, and placing the stack shell upon 
the ring. The sparks then fall back into the cupola if the stack 
is of a good height, and very few are thrown out at the top. 

The height of a cupola is the distance, from the top of the 
bottom plate to the bottom of the charging aperture. Manx- 
plans have been devised for utilizing the waste heat from a 
cupola, but the only practical means so far discovered is to 
construct a high cupola. The heat lost in a low cupola is then 
utilized in heating the stock in the cupola before it escapes 
from it. But all the heat is not utilized in this way, for a great 
deal of gas escapes unconsumed. This is shown by the in- 
crease in flame as the stock settles in the cupola. to a point at 
which the oxygen from the charging aperture combines with 
the escaping gas in sufificient quantity to ignite it, when it 
burns with a fierce flame above the stock. Still a great deal 
more heat is utilized in a high cupola than in a low one. 

It is well known among iron founders that a high cupola will 
melt more iron in a given time and with less fuel than a low one 
of the same diameter. Therefore the charging aperture should 
be placed at the highest practical point. There is a limit to 
the height at which the aperture in a small cupola can be 
placed, for where the diameter is small the iron in settling fre 
quently lodges against the lining and hangs up the stock. 



CONSTRUCTING A CUPOLA. 2C> 

When this occurs the stock has to be dislodged by a long bar 
worked down through from the charging aperture. If the 
aperture is placed at too great a height and the lodgment takes 
place near the bottom, the trouble cannot be remedied with a 
bar, and melting stops. Cupolas of large diameter may be 
made of almost any height desired, but there seems to be a 
limit to the height at which heat is produced in a cupola by the 
escaping gases, and we have arranged the following table from 
practical observation, giving the approximate height and size 
of door for cupolas of different diameters : 



Diameter 


Height of 


Size of Charging 


Melting Capac 


:ity 


Melting Capac 


Inside Lining, 


Cupola, 


Door, 


per Hour, 




per Heat, 


Inches. 


Feet. 


Inches. 


Tons. 




Tons. 


i8 


6-7 


15 X 18 


K-^ 




I — 2 


2C 


7-8 


18 X 20 


%-l 




2—3 


24 


8-9 


20 X 24 


I — 2 




3—5 


30 


9—12 


24 X 24 


2-5 




4 — 10 


40 


12 — 15 


30 X 36 


4-S 




8—20 


50 


15—18 


30 X 40 


6-14 




15—40 


60 


16 — 20 


30x45 


8—16 




25 — 60 



The melting capacity of a cupola varies with the kind of fuel' 
used. One-fourth more iron can be melted per hour with coke 
than with coal, and the meliing capacity per heat is greatly in- 
creased by the tapping of slag and the number of tuyeres. 

CH.'VRGING D(,OR. 

The charging door may be made in one or two sections and 
lined with fire brick or daubed with fire-clay; or it may be 
made of wire gauze placed in an iron frame. The charging 
door is of but little importance in melting, as it is seldom 
closed during the greater part of the heat, and is only of service 
to give draught to the cupola when lighting up, and to prevent 
sparks being thrown upon the scaffold during the latter part of 
the heat. 

.4IR CHAMBER. 

The air chamber for supplying the tuyeres with blast may be 
constructed either outside or inside the cupola shell. Wherb 



30 THE CUPOLA FURNACE. 

placed inside, the cupola must be boshed and the lining con- 
tracted at the bottom to make room for the chamber without 
enlarging the diameter of the cupola casing. When the cupola 
is large this can readily be done, and the boshing of the cupola 
increases its melting capacity ; but small cupolas cannot be 
contracted at the bottom to a sufficient extent to admit of an 
air chamber being placed inside without interfering with the 
dumping of the cupola. When placed inside, the chamber may 
be formed with cast iron staves made to rest upon the bottom 
plate at one end and against the casing at the other. The 
staves are flanged to overlap each other with a putty joint, and 
when new make a very nice air chamber. But when the lining 
becomes thin they become heated and frequently warp or 
break, and permit the blast to escape through the lining to so 
great an extent that the lining has to be removed and the 
staves replaced with new ones. 

The air chamber, when constructed inside the casing, should 
be made of boiler plate, and securely riveted to the casing to 
hold it in place and prevent leakage of blast through the lining. 
It must be constructed of a form to correspond with the bosh- 
ing of the cupola, and of a size to supply a sufficient quantity 
of blast to all the tuyeres. If these conditions cannot be met 
without reducing the cupola below 40 inches diameter at the 
tuyeres, then the air chamber should be placed on the outside, 
and any desired boshing of the cupola made by placing com- 
mon red brick behind the fire-brick lining. 

When the air chamber is placed upon the outside of the 
shell, it may be formed by a round cast iron or sheet metal 
pipe extending around the cupola, with branches extending 
down to each tuyere ; or it may be made of boiler plate and 
riveted to the shell. The great objection to the round or over- 
head air chamber is the numerous joints required in connecting 
it with each tuyere. These joints require continual looking 
after to prevent leakage of blast, and in many cases they are 
not examined from one year's end to another, and a large per 
cent, of the blast is frequently lost through leaky joints. The 



CONSTRUCTING A CUPOLA. 3 1 

best air chambers are those made of boiler plate and riveted to 
the cupola shell and securely corked. These air chambers are 
made of any shape that may suit the fancy of the constructor, 
and in many cases are very much in the way of the melter in 
makinglup the cupola, and of the moulders in removing the 
molten iron. They should not be made to extend out from the 
shell more than six inches, and any air capacity desired be given 
by extending the chamber up or down the shell. The air 
capacity should not be less than three or four times the area of 
the outlet of the blower, and may be much larger. The blast 
should be admitted to the chamber from the top on each side 
of the cupola. This arrangement places the pipes out of the 
way where the}- are least likely to be knocked and injured. 
When the tuyeres are placed low, the chamber may be made 
to extend down to the bottom plate. In this case the bottom 
plate must be made larger and the chamber cut away front and 
back for the tap and slag holes. 

When the tuyeres are placed high, the chamber should be 
placed up out of the way of the tap and slag holes, and riveted 
to the shell at both top and bottom. An opening should be 
made in the air chamber under each tuyere and covered with a 
piece of sheet lead, so that any molten iron or slag running into 
the chamber from the tuyeres will flow out and not injure or 
fill up the chamber. An opening should be placed in front of 
each tuyere for giving draught to the cupola when lighting up, 
and for the removal of any iron or slag that may run into the 
tuyere during a heat. These openings should not be made over 
three or four inches in diameter, and should each be provided 
with a tight-fitting door to prevent the escape of the blast. 

1 AP HOLE. 

One or more orifices are placed in the casing at the bottom 
plate for the removal of the molten iron from the cupola. 
These openings are known as tap holes, and in the casing are 
from six to eight inches wide and seven to nine inches high, 
curved or rounded at the top. The opening through the 



32 THK CUPOLA FL'KNACE. 

cupola lining is generally formed by the brick and presents a 
very ragged appearance after the lining has been in use a short 
time. This opening should be lined with a cast iron casting 
bolted to the cupola casing, and made to extend almost 
through the lining. The casing should be made slightly taper- 
ing with the large end inside, or ribbed, to prevent the front 
being pushed out by the pressure of molten iron retained in the 
cupola. For small cupolas, or a large cupola from which the 
iron is removed in large ladles, but one tap hole is required. 
But large cupolas melting over eight tons of iron per hour, 
from which the iron is taken in hand-ladles, require two tap 
holes. Two tap holes are sometimes placed in a cupola on 
opposite sides to shorten the distance of carrying the iron to 
the moulds. And two tap holes are also sometimes placed 
side by side so that each may be kept in better order through- 
out the heat. This is bad practice, for if the front is properly 
put in, one tap hole will run ofif all the iron a cupola is capable 
of melting. When two tap holes are put in they should be 
placed one in front and the other in the back or side of the 
cupola, so that the moulders will not be in each other's way 
when catching-in. 

THE SPOUT. 

A short spout must be [)rovided for conveying the molten 
iron from the tap hole to the ladles. This spout is generally 
made of cast iron, and is from six to eight inches wide, with 
sides from three to six inches high, and for small ladle work is 
from one to two feet long. For large ladle work it is made 
much longer. In some foundries where a long spout is only 
occasionally required, the spout is made in two sections and 
put together with cleats, so that an additional section may be 
put up to fill a large ladle and taken dovvn when it is filled. The 
spout should be long enough to throw the stream near the 
center of the ladle when filling. In a great many foundries 
the spout is laid upon the bottom plate, and- only held in place 
by the making-up of the front, and is removed after each heat. 



CONSTRUCTING A CUPOLA. 33 

This entails the loss of a groat deal of spout material each heat, 
and sometimes the spout is struck in the careless handling of 
ladles and knocked out of place, when much damage may be 
done. When not in the way of removing the dump, the spout 
should be securely bolted to the bottom plate. 

When it is desired to run a very small cupola for a greater 
length of time than an hour and a half, or a large one for a 
longer time than two hours and a-half, slag must be tapped to 
remove the ash of the fuel and dross of the iron from the 
cupola, to prevent bridging over and bunging up. The slag 
hole from which the slag is tapped is placed between the 
tuyeres, and below the lower level of the lower row of tuyeres. 
A hole is cut through the casing and lining from three to four 
inches in diameter, and a short spout or apron is provided to 
carry the slag out, so that it will fall clear of the bottom plate. 
The slag hold should be placed at the back of the cupola, or at 
the greatest possible distance from the tap hole, so that the 
slag will not be in the way of the moulders when catching the 
iron. The height at which a slag hole should be placed above 
the sand bottom depends upon how the iron is tapped. The 
slag in a cupola drops to the bottom and floats upon the sur- 
face of the molten metal, and rises and falls with it in the 
cupola. If the molten iron is held in the cupola until a large 
body accumulates, the slag hole must be placed high and the 
slag tapped when it has risen upon the surface of the molten 
iron to the slag hole. When the iron is withdrawn, the slag 
remaining in the cupola falls below the slag hole, and the hole 
must be closed with a bod to prevent the escape of blast. If 
the iron is drawn from the cupola as fast as melted, the slag 
hole is placed two or three inches above the sand bottom at 
the back of the cupola. The slag then lies upon the molten 
iron, or upon the sand bottom, and the slag hole may be 
opened as soon as slag has formed, and allowed to remain 
open throughout the heat. 
3 



34 THE CUPOLA FURNACE. 



TUYERES. 



A number of openings are made through the casing and lin- 
ing near the bottom of the cupola for admitting the blast into 
the latter from the air chamber or blast pipe. These open- 
ings are known as tuyeres. Tuyeres have been designed of all 
shapes and sizes, and have been placed in cupolas in almost 
every conceivable position, so there is little to be learned by 
experimenting with them, and the only things to be considered 
are the number, shape, size and position of tuyeres for different 
sized cupolas. For a small cupola, two tuyeres are sufficient. 
A greater number promotes bridging. They should be 
placed in the cupola on opposite sides, so that the blast will 
meet in the center of the cupola, and not be thrown against the 
lining at any one point with great force. The best shape for a 
small cupola is a triangular or upright-slot tuyere. These 
cause less bridging than the flat-slot or oval tuyere, and in 
small cupolas make but little difference in the amount of fuel 
required for the bed. When only two tuyeres are provided a 
belt air chamber around the cupola is not required, and the 
blast pipes are generally connected direct with each tuyere. 
In large cupolas the shape of the tuyeres selected makes but 
little difference in the melting, so long as they are of sufificient 
size and number to admit the proper amount of blast to the 
cupola, and so arranged as to distribute it evenly to the stock. 
The fiat-slot or oval tuyeres are generally selected for the 
reason that they require less bed than the upright- slot tuyere. 

The number of tuyeres required varies from four to eight, 
according to the size of the cupola and tuyeres. They should 
be of the same size and placed at uniform distances apart. A 
tuyere should never be placed directly over the tap or slag hole. 
The combined tuyere area should be from two to three times 
greater than the area of the blower outlet. The tuyere boxes 
or casings are made of cast-iron, and should be bolted to the 
cupola shell to prevent any escape of blast through the lining 
when it becomes old and shaky, or when lined with poor mate- 
rial and the grouting works out, as is sometimes the case. 



CONSTRUCTING A CUPOLA. 35 

The height at which tuyeres are placed in cupolas above the 
sand bottom varies from one or two inches to five feet, and 
there is a wide difference of opinion among founders as to the 
height at which they should be placed. When the tuyeres are 
placed low the iron must be drawn from the cupola as fast 
as melted, to prevent it running into them. In foundries 
where the iron is all handled in hand-ladles this can readily be 
done, and the tuyeres are placed low to reduce the quantity of 
fuel in the bed and make hot iron. In foundries in which 
heavy work is cast, and the iron handled in large ladles, the 
tuyeres are placed high, so that a large amount of iron may be 
accumulated in the cupola to fill a large ladle for a heavy piece 
of work. 

We do not believe in high tuyeres, and claim they should 
never be placed more than 10 or 12 inches above the sand 
bottom for any kind of work ; and if slag is not to be tapped 
from the cupola, they should not be placed more than two or 
three inches above the sand bottom. In stove foundries, in 
which cupolas of large diameter are employed and hot iron is 
required throughout the heat, the tuyeres are placed so low that 
the sand bottom is made up to within one inch of the bottom 
of those on the back and two or three inches at the front. 
This gives plenty of room below the tuyeres for holding iron 
without danger of it running into them. In cupolas of small 
diameter two inches is allowed at the back and three or four 
inches at the front. This insures a hot, even heat through- 
out the heat, if the cupola is properly charged, and a much less 
quantity of fuel is required for the bed than if the tuyeres were 
placed high. Molten iron is never retained in the cupola for 
this class of work, and the tap hole is made of a size to let the 
iron out as fast as melted and the stream kept running through- 
out the heat. 

Cupolas with high tuyeres are not employed for this class of 
work, for they do not produce a hot fluid iron throughout a 
heat without the use of an extraordinarily large per cent, of 
fuel, and when the tuyeres are extremely high thev do not 



36 THE CUPOLA PTTRNACE. 

make a hot iron with any amount of fuel. Nothing is gained by- 
holding molten iron in a cupola, for iron can be kept hotter in 
a ladle than in a cupola, and melted hotter with low than high 
tuyeres, and a cupola is kept in better melting condition 
throughout a heat by tapping the iron as fast as melted, 

TWO OR MORE ROWS OF TUYERES. 

It is the common practice to place all the tuyeres at the- 
same level, or in one row extending around the cupola. But 
two or more rows are frequently placed one above the other^ 
When a large number of rows are employed they decrease 
in area gradually from the lower to the top tuyere, and the- 
rows are generally placed very close together. When two 
rows are put in, the second row is made from one-half to one- 
tenth the area of the first row, and the two rows are placed 
from 8 to 1 8 inches apart. If the area of the second row is 
one-half that of the first, it is generally placed from 8 to lO' 
inches above the first row, and only when the tuyeres are very 
small are they placed at a greater height above the first row. 
When three rows are put in, the second row is made one-half 
the area of the first row, and the third row one-fourth the area 
of the second, and the rows are placed from 6 to lo inches 
apart. When tu}eres are placed in a cupola all the way up- 
to the charging door, those above the first or second row are 
made one inch diameter, and are placed from 12 to 14 inches 
above each other. 

The tuyere in the upper row may be placed directly over 
that in the row beneath it, or may be placed between two 
lower ones. Some cupola men claim that much better results 
are obtained by this latter plan, but we have never observed 
that it made any difference whether they were placed over or 
between those of the lower rows. 

Faster melting is secured with two or three rows of tuyeres 
than with one row in a cupola of the same diameter, and the 
melting capacity per hour is increased about one-fourth in 
melting large heats. When melting a small heat for the size 



CONSTRUCTING A CUPOLA. 37 

■of the cupola, nothing is gained by the additional rows of 
tuyeres, since a much larger quantity of fuel is required in the 
bed, for which there is no recompense by saving of fuel in the 
charges through the heat, and fast melting is seldom any great 
object in small heats, 

LINING. 

The casing may be lined with fire-brick, soapstone or other 
refractory substances. In localities where fire-brick cannot be 
■obtained, native refractory materials are used ; but fire-brick 
is to be preferred to native mineral substances. Cupola brick 
is now made of almost any shape or size required in cupola 
lining, and can be purchased at as reasonable a price as the 
common straight fire-brick. The curbed btick, laid flat, makes 
a more compact and durable lining than the wedge-shaped 
brick set on end, and is most generally used. When laying 
up a lining, the groutmg or mortar used should be of the same 
refractory material as the brick, so that it will not burn out and 
leave crevices between the brick, into which the flame pene- 
trates and burns away the edges of the brick. This material is 
jmade into a thin grout, and a thin layer is spread upon the 
bottom plate. The brick is then taken in the hand, one end 
dipped in the grout, and laid in the grout upon the plate. 
When a course or circle has been laid up, the top is slushed 
with grout to fill up all the cracks and joints, and the next 
•course is laid up and grouted in the same way. The joints are 
broken at each course, and the bricks are laid close together to 
make the crevices between them as small as possible, and pre- 
vent the flame burning away the corners in case the grouting 
.material is not good and burns out. 

Bricks that do not expand when heated are laid close to the 
•casing. Those that do expand are laid from a fourth of an 
inch to an inch from the casing, to give room for expansion, 
and the space is filled in with sand or grout. Brick of un- 
known properties should always be laid a short distance from 
the casing, to prevent the latter being burst by expansion of 
the lining. 



38 



THE CUPOLA FURNACE. 



The lining is made of one thickness of brick, and a brick is 
selected of a size to give the desired thickness of lining. In 
small cupolas, a four or five-inch lining is used, and in large 
cupolas a six or nine-inch lining. A heavier lining than nine 




SECTIONAL VIEW OF CUPOLA. 



inches is seldom put in, except to reduce the diameter of the 
cupola or prevent the heating of the shell. In these cases, a 
filling or false lining of common red brick is put in between the 



CONSTRUCIING A CUPOLA, 39 

fire-brick and shell. The stack lining is seldom made heavier 
than four inches for any sized cupola, as the wear upon it is not 
very great, and a four-inch lining lasts for a number of years. 
The stack lining is laid up and grouted in the same way as the 
cupola lining. 

ARRANGEMENT OF BRACKETS, ETC. 

In Fig. I is shown the manner in which brackets or angle 
irons are put into a cupola for the support of the lining in sec- 
tions upon the casing. The brackets are made of heavy boiler 
plate from five to six inches wide, circled to fit the casing and 
bent at a square angle. The part riveted to the casing is made 
four inches long and secured with two or three rivets. The 
bracket or shelf for the support of the lining is made from one 
and a half to two inches long. The brackets ire placed about 
two feet apart around the casing and in rows from two to three 
feet above each other. These brackets are but little in the way 
when laying up a lining, and support the latter so that a section 
may be taken out and replaced without disturbing the re- 
mainder. 

Angle iron is by many preferred to brackets for the support 
of the lining. It is put in bands extending all the way around 
the casing and riveted to it. These bands not only support the 
lining but act as braces to the casing, and in some respects are 
a better support for the lining than brackets. They catch and 
hold in place all the grouting or sand that may work out of the 
lining between the casing, and give a more even support to the 
lining, but with their use it is sometimes more difficult to fit the 
brick around when laying up a lining. Still, angle iron has 
generally taken the place of brackets and is put in all the mod- 
ern cupolas. The brackets or angle irons should not be made 
to extend out from the casing more than one and a half or two 
inches, for if they do they are liable to be burned off when the 
lining becomes thin and let the iron or heat through to the 
casing. One and a half inches are sufficient to support the 
lining if the bricks form a circle to fit the casing. No supports 



40 THE CUPOLA FURNACE. 

should be put in at the melting zone, for the lining frequently 
burns very thin at this point, even in a single heat. It is not 
necessary to put in any below the melting zone, and the first 
onis should be placed at the upper edge of the zone, and from 
this up they should be put in at every two or three feet. 

The weight of brick placed upon the lower courses in a 
cupola lining is suflficient to crush most of the soft cupola brick, 
and were it not for the support given to three sides of them in 
the lining they would, by the great weight placed upon them, 
be reduced to a powder. As a lining burns out it becomes 
thin more rapidly at the bottom, and it often happens that the 
lining at the melting zone is reduced to one-half its thickness, 
or even less, in a few heats, and this reduced lining often has to 
support a lining of almost full thickness for the entire cupola, 
and in some cases also the stack lining. The cohesive force of 
these bricks is reduced by the intense heat in the cupola, and 
when subjected to so great a pressure and heated they are 
crushed and the lining gradually settles and becomes shaky. 
This settling is so great with some qualities of brick that in 
cupolas having no frame riveted to the casing around the 
charging aperture, the arch over the- door frequently settles so 
low that it becomes necessary to rebuild it to maintain the full 
size of the opening. 

Brick does not give the best results when subjected to so great 
a pressure and heated to a high temperature. Therefore, in all 
cupolas, brackets or angle irons should be put in every two or 
three feet for the support of the lining on the casing, and the 
latter should be made heavy enough to support the entire 
lining when a section has been burned out or removed. 

In the illustration ( Fig. I ) is also shown a way for reducing the 
size and weight of the bottom doors and preventing the casing 
from rusting off at the bottom. In many of the large cupolas re- 
quiring heavy sand bottoms, the bottom plate can be made to 
extend into the cupola from three to six inches all round witii- 
out in the least interfering with dumping, and the first few 
courses of brick sloped back from the edge of the plate to the 



CONSTRUCTING A CUPOLA, 4 1 

regular thickness of lining to prevent sand lodging on the edges 
of the plate around the lining. By this arrangement in large 
cupolas, the diameter of the doors may be reduced from six to 
ten inches, and very much lightened, and less sand will be re- 
quired, for the sand bottom and the dump fall as freely as 
when the doors are the full size of the cupola. 

Cupolas that are not in constant use absorb a great deal of 
moisture into the lining and are constantly wet around the 
bottom plate, and ligiit casings are eaten away by rust in a 
short time. To prevent this the first one or two courses of 
brick can be laid a few inches from the casing and a small air 
chamber formed around the cupola at this point. If this 
chamber is supplied with air from a few small holes through 
the iron bottom or casing, the latter is kept dry, and rusting is 
prevented. 

In the illustration (Fig. i) is shown the triangular-shaped 
tuyere in position in the lining. This tuyere prevents bridging 
to a greater extent than any other, and is, for a small cupola, 
one of the very best shapes. It is formed with a cast iron 
frame set in the lining, and each tuyere may be connected with 
a separate pipe, as shown, or they may be connected with an 
air belt extending around the cupola. 

Bottom plates may be cast with a light flange around the 
edge, as shown in the illustration (Fig. i), or made perfectly 
flat on top ; but it is better to cast them with a small flange or 
bead for holding the shell in place upon the plate, and thus 
make the cupola to have a more finished look around the 
bottom. 

FIRE PROOF SCAFFOLDS. 

The charging door or opening through which fuel and iron 
are charged into a cupola is placed at so great a height from 
the floor that it is necessary to construct a platform or scaffold, 
upon which to place the stock, and from which to charge it 
into the cupola. For heavy work, this scaffold is generally 
placed on three sides of the cupola, leaving the front clear for 



42 THE CUPOLA FURNACE. 

the swinging of crane ladles to and from the spout; but for 
light work the scaffold frequently extends all the way around 
the cupola to give more room for placing stock upon it. I'he 
distance the floor of a scaffold is generally placed below the 
charging door is about two feet, but that distance varies, and 
floors are frequently placed on a level with the door or three 
or four feet below it to suit the kind of iron to be melted or the 
facilities for placing stock upon the scafifold from the yard. 
The scaffold and its supports are more exposed to fire than 
almost any other part of a foundry, for live sparks are thrown 
from the charging door upon the scaffold floor, and molten 
iron, slag, etc., are frequently thrown against its supports and 
the under side of the door with considerable force when dump- 
ing the cupola. Numerous plans have been devised to make 
scaffolds fire-proof and prevent the foundry from being set on 
fire. In many of the wooden foundry buildings the scafifold is 
constructed entirely of wood, and to render it fire-proof, the 
supports and under side of the floor are covered with light 
sheet iron to protect them from molten iron, slag, etc., when 
dumping. The covering of the wood-work of a scaffold in this 
wa}' is very bad practice, for while it protects the wood from 
direct contact with the fire, it also prevents it from being 
wetted, and in a short time the wood becomes very dry and 
very combustible. The thin covering of sheet iron is soon 
eaten away with rust, leaving holes through which sparks may 
pass and come in contact with the dry wood and ignite it under 
the sheet iron where it cannot be seen, and the cupola men, 
after wetting down the dump very carefully, may go home 
leaving a smouldering fire concealed by the sheet iron cover- 
ing which may break forth during the night and destroy the 
foundry. It is better to leave .all the wood- work entirely un- 
covered and exposed to the fire and heat, and wet it in exposed 
places before and after each heat ; the wood is then kept 
dampened and is not so readily combustible as when covered 
with sheet iron, and if ignited the fire may be seen and ex- 
tinguished before the men leave for home after their day's work 



CONSTRUCTING A CUPOLV. 43 

is done. In many of the wooden foundry buildings the cupola 
is placed outside the foundry building, and a small brick house 
or room is constructed for it and the molten iron run into the 
foundry by a cupola spout extending through the wall. In 
this way a scafifold may be made entirely fire-proof by putting 
in iron joists and an iron or brick floor, and putting on an iron 
roof. We saw a scaffold and cupola house at a small foundry 
in Detroit, Mich., about twenty years ago, that was constructed 
upon a novel plan and was perfectly fire-proof. The house was 
twelve feet square and constructed of brick, the scaffold floor 
was of iron and supported by iron joists, the walls were perpen- 
dicular to five feet above the scaffold floor, and from this point 
they were contracted and extended up to a sufficient height to 
form a stack three feet square at the top. The cupola was 
placed at one side of this room and the cupola-house, and the 
spout extended through the wall into the foundry: the open 
top of the cupola extended about two feet above the scaffold 
floor, and its stack was formed by the contracted walls of the 
cupola-house. There were no windows in the house, and only 
one opening above for placing stock upon the scaffold, and one 
below for removing the dump and making up the cupola, both 
of which openings were fitted with iron door frames and doors, 
and could be tightly closed. When lighting up, the scaffold 
door was closed to give draught to the cupola, and when burned 
up the door was opened and the cupola charged from the scaf- 
fold. Sparks from the cupola when in blast fell upon the 
scaffold floor and were never thrown from the top of the stack 
or cupola-house upon the foundry roof or the roofs of adjoining 
buildings, and when the doors were closed the scaffold was as 
fire-proof as a brick stack. The great objection to this scaffold 
was the gas from the cupola upon the scaffold when the blast 
was on, and the intense heat upon the scaffold in warm weather 
or when the stock got low in the cupola. 

The best and safest scaffolds are those constructed entirely 
of iron, or with brick floors and supported by iron colunms, or 
brick walls, and made of a sufficient size to admit of wood or 



44 THE CUPOLA FURNACE. 

Other readily combustible cupola material being placed at a safe 
distance from the cupola. The cupola scaffold in the foundry 
of Gould & Eberhardt, Newark, N. J., is constructed of iron 
supported by iron columns and brick walls, and is of sufficient 
size and strength to carry two car-loads of coke, one hundred 
tons of pig and scrap iron, and all the wood shavings and other 
materials required for the cupola. In the new iron foundry 
building recently erected by The Straight Line Engine Com- 
pany, Syracuse, N. Y., the scafifold is constructed entirely of iron 
and supported by the iron columns which support the foundry 
roof. It extends the entire length of the foundry, affording 
ample room for storing iron, coke, wood and all cupola sup- 
plies, thus doing away with a yard for storing such material, and 
placing them under the foundry roof and convenient for use. 
Scaffolds of this kind greatly reduce the expense of handling 
cupola stock, and also reduce the rate of insurance on foundry 
buildings. 



CHAPTER IV. 



CUPOLA TUYERES. 



The cupola furnace may be supplied with the air required 
for the combustion of the fuel by natural draft induced by a 
high stack, a vacuum created by a jet of steam, or by a forced 
blast from a fan or blower. In either case, the air is generally 
admitted to the cupola through openings in the sides near the 
bottom. These openings are known as tuyeres or tuyere holes. 
The location, size, number and shape of these tuyeres are a 
matter of prime importance in constructing a cupola, and are a 
subject to which a great deal of attention has for years been 
given by eminent and practical foundrymen, and to these men 
is due the credit for the advancement made in the construction 
of cupolas. 

It is only a few years since lO to 15 tons were considered a 
large heat for a cupola, and when a large casting was to be 
poured two or more cupolas were run at the same time and 
the greater part of a day consumed in melting. Now 60 tons 
are melted in one cupola in four hours for light foundry work, 
and hundreds of tons are melted in one cupola in steel works 
without dropping the bottom. This improvement in melting is 
largely due to the improvement in the size, shape and arrange- 
ment of tuyeres. 

There have been epidemics of tuyere-inventing several times 
in this country in the past twenty-five years, and during these 
periods it has been almost impossible for an outsider to get a 
look into a cupola for fear the great secret of melting would be 
discovered in the shape of the tuyere and made public. Dur- 
ing these epidemics tuyeres of almost every conceivable shape 
have been placed in cupolas, and great results in melting, 

(45) 



46 THE CUPOLA FURNACE. 

claimed for them. Many of these tu>'ere.s were soon found to 
be compHcated and impracticable, or the advantage gained by 
their use in mehing was more tiian offset by extravagant use of 
fuel. 

It would be useless for us to describe all the tuyeres we have 
seen employed, for many of them were never used out of the 
foundry in which they were invented, and there only for a 
short time. We shall, therefore, describe only a few of those 
that have been most extensively used or arc in use at the 
present time. 

The round tuyere is probably ihe oldest or first tuyere ever 
placed in a cupola. It was used in cupolas and blast furnaces 
in colonial days in this country, and long before that in France 
and other countries. In the old-fashioned cast iron stave 
cupolas three round tuyeres were generally placed in a row, 
one above another, on opposite sides of the cupola. The first 
or lower tuyere was placed from i8 to 24 inches above the 
sand bottom, and the others directly over it from 3 to 4 inches 
apart. The tuyere nozzle or elbow was attached to the blast- 
pipe by a flexible leather hose, and first placed irr the lower 
tuyere and the two upper tuyeres were temporarily closed with 
clay. When a small heat was melted the nozzle was permitted 
to remain in the lower tuyere throughout the heat. But when a 
large heat was melted and the cupola melted poorly at any part 
of the heat, or if molten iron was to be collected in the cupola for 
a large casting, the clay was removed from the upper tuyeres, 
and the nozzle removed from one to the other, as required, and 
the lower tuyeres were closed with clay. 

In these cupolas the tuyeres were generally too small to 
admit a proper volume of blast to do a good melting. In one 
of 28 inches diameter we saw at Jamestown, N. Y.. the orig- 
inal tuyeres were only 3 inches in diameter. Two tuyeres of 
this size could not possibly admit a sufficient volume of blast 
to do good melting in a cupola of the above diameter, and in 
this one they had been replaced by two of a much larger diam- 
eter placed at a lower level than the old ones. The round 



CUPOLA TUYt:RES. 



47 



tuyere is still extensively used in small cupolas where the 
tuyeres can be made of a diameter not to exceed 5 or 6 inches, 
but in large cupolas it has generally been replaced by the flat 
or oval tuyere, which admits the same volume of blast and per- 
mits of a smaller amount of fuel being used in the bed than 
could be used with a round tuyere of large area. 

OVAL TUYERE. 

In Fig. 2 is shown the oval or oblong tuyere now extensively 
used. It is made of different sizes to suit the diameter of 
cupola, the most common sizes used being 2 x 6, 3 x 8. and 
4x12 inches. They are laid flat in the lining and generally 
supplied from an outside belt air chamber. This tuyere is the 
one most commonly used by stove, bench, and other foundries 
requiring" very hot iron for their work. They are placed very 
low, generally not more than two or three inches above the 



Fil; 



Fig. 3. 





CUPOLA TUYERF.S — OVAL TUYERE. 



EXPANDED TUYERE. 



sand bottom, and in large cupolas the slope of the bottom fre- 
quently brings it up to the bottom of the tuyeres on the back 
side of the cupola. This tuyere admits the blast to a cupola 
as freely as a rounded one of the same area, and the tendency 
of the stock to chill over the tuyeres in settling and bridge the 
cupola is no greater than with a round tuyere of the same 
capacity. It admits of a lower bed than the round tuyere, 
and is to be preferred to the latter for cupolas requiring tuy- 
eres of a larger area. 

EXPANDED TUYERE. 

In Fig. 3 is seen the expanded tuyere, which is made larger 
at the outlet than at the inlet. It is reduced at the inlet so 



48 THE CUPOLA FURNACE. 

that the combined tuyere area may correspond with the outlet 
of the blower and equalize the volume of blast entering the 
cupola at each tuyere from the air belt. It is expanded at the 
outlet to permit the blast to escape freely from the tuyeres into 
the cupola, and in case the stock settles in the front of the 
tuyere in such a way as to close up part of it, there may still be 
sufficient opening for the full volume of blast entering the 
tuyere to pass into the cupola. The tuyere is made from two 
to four inches wide at the inlet and six to twelve inches long. 
The width of the outlet is the same as that of the inlet, and the 
length of the outlet is from one-fourth to one-half longer than 
the inlet. The tuyere is laid flat in the lining, the same as the 
oval tuyere, and the only advantage claimed for it over the 
latter is that it cannot be closed so readily by the settling of 
the stock and the chilling of the iron or cinder in front of it. 
The expanded tuyere is preferred by many to the oval tuyere 
on this account, and is extensively used at the present time. 
It has been almost universally adopted by cupola manufac- 
turers. 

DOHERTY lUYERE. 

In Fig. 4 is seen the Doherty arrangement of tuyeres, designed 
by Mr. Doherty of the late firm of Bement & Doherty, Philadel- 
phia, Pa., and employed in the Doherty cupola, a cupola that was 
extensively used in Philadelphia about twenty-five years ago. 
The arrangement consists of two or more round tuyeres placed 
in the lining and at an angle to it. instead of passing straight 
through the lining as tuyeres generally do. The blast pipes 
connecting with each tuyere were placed at the same angle as 
the tuyere, the object being to give the blast a whirling or 
spiral motion in the cupola. The blast took the desired course, 
as could be plainly seen by its action at the charging door, and 
it had the appearance of making a more intense heat in the 
cupola than when delivered from the straight tuyere. But this 
appearance was deceptive, and after careful investigation it was 
found that no saving in fuel was efifected, or faster or hotter 
melting done on account of this motion of the blast. The 



CUPOLA TUYERES. 



49 



cupolas and tuyeres were, however, constructed of proper pro- 
portions, and were a decided improvement on the small tuyere 
cupolas in use at that time. Many of them were placed in 
foundries and are still in use, but no importance is attached to 
the spiral motion of the blast. 

SHEET BLASr TUYERE. 

In Fig. 5 is seen the horizontal slot tuyere. This tuyere 

Fig. 4. 



Fig. 5. 





SHEET BLAST TUYERE. 



OOHERTY TUYERE. 

consists of a slot from one to two inches wide, extending one- 
third around the cupola on each side, or a continuous slot ex- 
tending all the way around the cupola. The slot is formed by 
two cast-iron plates, on one of which are cast separating bars 
to prevent the plates being pressed together by the weight of 
the lining or warped by the heat. This tuyere is known as the 
sheet blast tuyere. It admits of a smaller amount of fuel being 
used for a bed than any other tuyere placed in a cupola at the 
same height above the bottom. It distributes the blast equally 
to the stock, and does fast and economical melting in short 
heats. But the tendency of the cupola to bridge is greater 
than with almost any other tuyere, and a cupola furnished with 
it cannot be run successfully for a greater length of time than 
two hours. 

MACKENZIE TUYERE. 

In Fig. 6 is seen the Mackenzie tuyere, designed by a Mr. 
Mackenzie of Newark, N. J., and used in the Mackenzie cupola. 
This is a continuous slot or sheet blast tuyere, but differs from 
the one just described in that the cupola is boshed and the bosh 



50 



THE CUPOLA FURNACE. 



overhangs the slot from four to six inches. The slot is pro- 
tected by the overhanging bosh and cannot be closed up by the 



Fig. 6. 




MACKENZIE TUVEKE. 

settling of the stock. The Mackenzie cupola with this tuyere 
is constructed of an oval or oblong shape, with an inside belt 
air chamber. The blast enters the air chamber from a tuyere box 
at each end of the cupola, and passes into the latter through 
a two-inch slot extending all the way around it. 

BLAKENEY rUYERK. 

In Fig. 7 is seen the Blakeney tuyere used in the Blakeney 
cupola constructed by The M. Steel Company, Springfield, Ohio. 
This tuyere is a modification or an improvement on the sheet 
blast tuyere, and extends all the way round the cupola. It is 



CUPOLA TUYERES. 



51 



supplied from an outside belt air chamber riveted to the shell. 
The blast is conducted to the air chamber through one pipe, and, 
striking the blank spaces sidewise in rear of chamber, passes 
all around through the curved tuyeres into the centre of the 
furnace. This tuyere admits the blasts freely and evenly to the 
cupola and very good melting is done with it. All the tuyeres 
described above may be used with either coal or coke. 

HORIZONTAT, AND VERTICAL SLOT TUYERE. 

In Fig. 8 is seen the horizontal and verticle slot tuyere. 
This was designed for coke, and we have seen it used in but 

Fig. 7. 




BLAKENEY TUYERE. 

one cupola, a 40-inch one. One tuyere was placed on each 
side of the cupola. The horizontal slot of each tuyere, i inch 

Fig. 8. 




HORIZONTAL AND VERTICAL SLOT TUYERE. 



wide, e.xtended one-third way round the cupola, and the 
verticle slots, i inch wide and 12 inches long, were placed 
above it as shown. The tuyere did excellent melting, and the 
cupola could be run for a long time without bridging. 



52 



THE CUPOLA FURNACE, 



REVERSED T TUYERE. 

In Fig. 9 is seen a verticle and horizontal slot or reversed "T" 
tuyere, also used for coke. The slots in this tuyere are from 
two to three inches wide and ten to twelve inches long. From 
two to eight of these tuyeres are placed in a cupola, according 
to the diameter. This tuyere has been extensively used, and 
is said to be an excellent one for coke-melting. 

In Figs. lO and ii are seen the vertical slot tuyeres used 
principally in cupolas of small diameter to prevent bridging. 



Fig. 9. 



Fig. 10. 



Fig II. 








REVERSED X TUYERE. 



VERTICAL SLOT TUYERE. 




VERTICAL SLOT TUYERE 



They are made from two to three inches wide and ten to 
twelve inches long, and two or more are placed in a cupola at 
equal distances apart. 



TRUESDALE REDUCING lUYERE. 

In Fig. 12 is seen the Truesdale reducing tuyere designed 
by Mr. Truesdale of Cincinnati, Ohio, and extensively used in 
cupolas in that vicinity about 1874. The tuyere consisted of 
one opening or tuyere placed directly over another until six, 
eight or ten tuyeres were put in. The lower tuyere was made 
three or four inches in diameter, and tuyeres above it were 
placed one inch apart, and each one made of a smaller diam- 
eter until they were reduced to one inch. The bottom rows of 
tuyeres were placed two, four or six inches apart, and the 
tuyeres in each succeeding row were placed further apart, were 
of a smaller diameter and admitted less blast to the cupola to- 



CUPOLA TUYERES. 



53 



ward the top of the bed than at the bottom. The cupolas were 
generally boshed, and the tuyeres supplied from an inside belt 
air chamber, formed of cast iron staves, to which the tuyeres 
were- attached by cleats or dovetails cast on the stays. Very 
fast melting was done in cupolas with this tuyere, but the ten- 
dency to bridge in cupolas of small diameter was so great that it 
could not be used in them. In large cupolas, however, it gave 
excellent results, and is still in use in numerous foundries. 

LAWRENCE REDUCING TUYERE. 

In Fig. 13 is seen the Lawrence reducing tuyere designed by 
Frank Lawrence of Philadelphia, Pa., and used in the Lawrence 
cupola, built by him. This tuyere was designed for either coal 

Fig. 12. 



O 



Fk;. 13. 



Fig. 14. 



O 

O 

o 



TRUESDALE REDUCINC; 
TUYERE. 





TRIANGULAR TUYERE. 



LAWRENCE REDUCING 
TUYERE. 



or coke melting, and works equally well with either. The 
opening at the bottom is from 3 to 4 inches square, and the 
slot from 10 to 12 inches long, from i to i^ inches wide at the 
bottom, and tapers to a point at the top. The tuyeres are 
placed in the cupola from 6 to 12 inches apart, and supplied 
from a belt air chamber inside the casing. The air chamber in 
this cupola was first formed with cast-iron staves, and the tuy- 
eres were held in place by cleats cast upon the staves. But the 



54 THE CUPOLA FURNACE. 

staves were found to break after repeated heating and cooling, 
and a boiler-iron casing is now used for the air chamber. This 
tuyere and cupola do excellent melting, and a great many of 
them are now in use. 

TRIANGULAR TUYERE. 

In Fig. 14 is seen the triangular tuyere, designed by the 
writer over 25 years ago to prevent bridging in small cupolas, 
and is extensively used in both small and large cupolas, with 
either coal or coke. This tuyere may be made with the base 
and sides of equal length, forming an equilateral triangle, or 
the sides may be made longer than the base, bringing the 
tuyere up to a sharp point at the top to prevent bridging; or 
the sides may be extended up to a sufficient height to form a 
reducing tuyere. 

The Magee Furnace Company, Boston, Mass., placed this 
tuyere in their large cupola, constructed to melt iron for stove 
plate, about fifteen years ago, and it has been in constant use 
ever since, giving excellent results in melting with coal and 
coke. In this cupola, which is 5 feet 4 inches diameter at the 
melting point, the tuyere is 9 inches wide at the base and 16 
inches high. It was not thought best to extend it up to 
a point at so sharp an angle, and the top was cut off, leaving 
the opening 2 inches wide at the top. This tuyere has been 
arranged to take the place of the Truesdale reducing tuyere, 
and has been made from 6 to 8 inches wide at base and 24 to 
30 inches high, running up to a point. It has also been used 
in imitation of the Lawrence reducing tuyere, and made from 3 
to 4 fnches wide at base and 12 to 16 inches high, 

WATER TUYERE. 

In Fig. 15 is seen the water tuyere. This tuyere is designed 
to be used in cupolas or furnaces where the whole or part of 
the tuyere is exposed to an intense heat and liable to be melted 
or injured, as is the case with tuyeres placed in the bottom of a 
cupola or in furnaces where a hot blast is used. 



CUPOLA TUYERES. 



55 



The tuyere or metal surrounding the tuyere opening is cast 
hollow and filled with water, or one end is left open and a spray 
thrown against the end exposed to the heat from a small pipe, 
as shown in the illustration. The tuyere is also made with a 



Fig. i6. 



Fu;. 15. 




WATER TUYEKE. 




COLLIAU TUYERE. 



coil of gas pipe cast inside of it, through which water constantly 
flows. The water tuyere is never used when the tuyeres are 
placed in the sides of the cupola, but it has been used in 
cupolas in which the tuyere was placed in the bottom and 
exposed to the heat of molten iron, cinder and slag. When 
used in this way it is fixed in the centre of the bottom, and 
is made from i to 3 feet long, the mouth being placed at a 
sufificient height above the sand bottom to prevent molten 
iron or slag overflowing into it. The part of the tuyere ex- 
tending up in the cupola and exposed to the heat is protected 
and prevented from melting by the stream of water. For this 
purpose the coil gas pipe tuyere is better than the hollow or 
spray tuyere just described. 



56 THE CUPOLA FURNACE. 

COLLIAU TUYERE. 

In Fig, i6 is seen the Colliau double tuyere designed by the 
late Victor Colliau of Detroit, Michigan, and used in the Colliau 
cupola. In this cupola the tuyeres are placed in two rows one 
above the other in place of one row as in the ordinary cupola. 
The first row is placed at about the same height above the sand 
bottom as in the ordinary cupola and the second row from 12 
to 18 inches above the first row. The first row consists of flat, 
slightly expanded tuyeres similar to that shown in Fig. 3 ; they 
are made from 2 to 4 inches wide and 6 to 14 inches long, ac- 
cording to the size of the cupola. The tuyeres in the second row 
are made round and from 2 to 4 inches diameter. The tuyeres 
in the first row pass straight into the cupola through the lining, 
and those in the second row are pointed downward at a sharp 
arigle, as shown in the cut. The object of the second row is to 
furnish suflEicient oxygen to consume the escaping gases and 
create a more intense heat at the melting point than is obtained 

with the single row of tuyeres from the same amount of fuel. 

I 

WHITING TUYERE. 

The Whiting tuyere, used in the Whiting cupola, manufac- 
tured by the Whiting Foundry Equipment Company, Chicago, 
111., was designed by Mr. Whiting, a practical foundryman of 
Detroit, Mich., as an improvement on the Colliau tuyere. The 
Whiting tuyere is a double tuyere, but dififers somewhat in 
arrangement from the Colliau. The first row are flat, slightly 
expanded tuyeres, and the second row are of the same shape 
and rr)ade larger in proportion to the lower row than the 
Colliau, and the two rows are not placed at so great a distance 
apart. Both the upper and lower rows pass straight into the 
cupola. 

CHENNEV TUYERE. 

The Chenney tuyere, designed by the late Mr. Chenney, a 
practical foundryman of Pittsburg, Pa., is a double tuyere 
very similar in arrangement to the Colliau and Whiting, the 
only difference being that both the upper and lower rows 
point downward at a sharp angle to the lining. 



CUPOLA TUYERES. 57 

THE DOUBLE TUYERE. 

The double or two rows of tuyeres appears to have first been 
designed and put into practical use about 1854 by Mr. Ireland, 
a practical English foundryman and cupola builder. In Ire- 
land's cupolas, many of which were in use in England about 
that time, the tuyeres were placed in two rows about 18 inches 
apart. Those in the upper row were of only one-third the 
diameter of those in the lower, and twice the number of 
tuyeres were placed in the upper row as were in the lower. 
The slag hole was also used by Ireland in his cupola, which 
was run for a great many hours without dumping or raking 
out, as was the custom in those days. These cupolas appear 
to have given very good results in long heats, but in short 
heats they were not as satisfactory, and in more recent patents 
obtained by Mr. Ireland the upper row of tuyeres was aban- 
doned. The double tuyere was also used in Voisin's cupola, 
another English cupola designer and constructor, and in 
Woodward's steam jet cupola, also an English cupola, many 
years before it was introduced into this country by Mr. CoUiau, 
about 1876. 

It is claimed for the double tuyere that the second row con- 
sumes the gases which escape with the single tuyere, and, 
therefore, a great saving in fuel is effected in melting. That a 
more intense heat is created in the cupola at the melting zone 
by the double tuyere cannot be disputed, for the destruction of 
lining is much greater at this point that with the single tuyere ; 
but on the other hand, that any saving in fuel is effected has 
not been proven by comparative tests made in melting with 
the double tuyere cupola and the single tuyere cupola, when 
properly constructed and managed. On the contrary it has 
been proven that the single tuyere cupola is the most econom- 
ical in fuel and lining. That the double tuyere melts iron 
faster than the single in cupolas of the same diameter is 
undisputed, and as between the single and double it is only 
a question whether the time saved in melting more than 
compensates for the extra expense of lining. When a double 



58 THE CUPOLA FURNACE. 

tuyere cupola is run to its full capacity, the consumption of fuel 
per ton of iron is about the same as with the single tuyere, but 
in small heats it is much greater. This is due to the large 
amount of fuel required for a bed, owing to the great height of 
the upper tuyeres above the sand bottom ; for the bed must be 
made about the same height above the upper tuyeres as above 
the lower in a single tuyere cupola, and no greater amount of 
iron can be charged on the bed with the double tuyere than 
with the single. When constructing or ordering a double 
tuyere cupola, the smallest one that will do the work should be 
selected, so that it may be run to its fullest capacity each heat 
and the best results obtained in melting. 

THREE ROWS OF TUYERES. 

A number of large cupolas have been constructed with three 
rows of tuyeres, for the purpose of doing faster melting than 
can be done with the single or double tuyere cupola. Prob- 
ably one of the best melting cupolas of this kind in use at the 
present time is one constructed by Abendroth Bros., Port 
Chester, N. Y., to melt iron for stove plate, sinks, soil pipe and 
plumbers' fittings. This cupola is 54 inches diameter at the 
tuyeres and 72 inches at the charging door, and is supplied 
with blast from 36 tuyeres, placed in the cupola in three hori- 
zontal rows [O inches apart, 12 tuyeres being placed in each row. 
The tuyeres in the first row are 6 inches square, those in the 
second row 4 inches square, and those in the third row 2 
inches square. This cupola melts 60 tons of iron in four hours, 
which is probably the fastest melting done in the country for 
the same number of hours for light work requiring hot iron. 
In the double or triple tuyere cupola the upper tuyeres maybe 
be placed directly over a tuyere in the lower row, or they may 
be placed between the tuyeres of the lower row at a higher 
level. In Ireland's cupolas double the number of tuyeres were 
placed in the upper row than were in the lower row, so that one 
was placed directly over each tuyere in the lower row and one 
between. In the modern double tuyere cupola the same num- 



CUPOLA TUYERES. 59 

ber of tuyeres are placed in each row, and the upper tuyeres 
are generally placed between those in the lower row. The 
object in placing these tuyeres in a cupola, as stated before, is 
to supply the oxygen to burn the unconsumed gases escaping 
from the combustion of fuel at the lower tuyeres. If a proper 
amount of blast is admitted at the lower tuyere the cupola is 
filled with gases at this point, and it does not make any dififer- 
ence whether the upper tuyeres are placed over or between the 
lower ones, so long as they are only to supply oxygen to 
consume the gases with which the cupola is filled. If this 
theory of producing heat by consuming the escaping gases 
from the combustion of fuel is correct, they can be consumed 
at any point in the cupola, and the row of tuyeres for this pur- 
pose should be placed above the bed, and the gas burned in 
the first charge of iron to heat it and prepare it for melting be- 
fore it settles into the melting zone. To consume these gases 
only, the tuyeres should be small, and the number of them in 
the upper rows should be two or three times greater than in 
the lower row, so as to supply oxygen to all parts of the cupola, 
and not permit the gases to escape unconsumed between the 
tuyeres. If the tuyeres in the second and third rows are made 
too large in proportion to those in the lower row, the supply of 
oxygen is too great for the combustion of the gases, and the 
effect is to cool the iron. In the modern double tuyere cupola 
this theory is not Carried out, for the tuyeres in the second row 
are made big, and admit such a large volume of oxygen at one 
point that if they were placed high their efTect would be to 
cool the iron rather than to heat it. But they are placed low 
so as to force the blast into the bed and give a deeper melting 
zone, and their effect is to cause a more rapid combustion of 
fuel and do faster melting than is done in the single tuyere 
cupola of the same diameter. 

GREINER TUYERE. 

In Fig. \'] is seen the Greiner tuyere. The novelty of this 
device consists in a judicious admission of blast into the 



6o 



THE CUPOLA FURNACE. 



Fig. 17. 



upper zones of a cupola, whereby the combustible gases are 
consumed within the cupola and the heat utilized to pre-heat 
the descending charges, thereby effecting a saving in the fuel 

necessary to melt the iron when it 
reaches the melting zone. This device 
consists of a number of upright gas 
pipes attached to the top of the wind 
box around the cupola, with branch 
pipes of I inch diameter extending into 
the cupola through the lining and about 
I foot apart, from a short distance above 
the melting zone to near the charging 
door. It is claimed that these small 
pipes admit a sufficient amount of oxy- 
gen to the cupola to burn the carbonic 
oxide produced by the carbonic acid 
formed at the tuyeres absorbing carbon 
from the fuel in its ascent. A great 
saving in fuel is thus effected by consuming this gas and pre- 
paring the iron for melting before it reaches the melting zone. 
While, when the first edition of this book was published, quite 
a number of cupolas with this device were in use in this 
country, the Greiner theory of melting has now been prac- 
tically abandoned, and we do not know of a single set of these 
tuyeres being in use at the present time. 




GREINER TU-YERE. 



ADJUSTABLE TUYERES. 

Tuyeres are sometimes placed in a cupola so that they may 
be adjusted to conform to the size of the heat to be melted or 
the way the iron is to be drawn from the cupola, and thus save 
fuel in the bed. They are placed low when the heat is small 
or the iron is drawn from the cupola as fast as melted, and 
placed high when the heat is large or when iron is to be held in 
the cupola for a large piece of work. One of the best arranged 
cupolas of this kind we have seen is that of the Pennsylvania 
Diamond Drill and Manufacturing Company, Birdsboro, Pa. 



CUPOLA TUYERES. 6l 

The air belt extending around the cupola is riveted to the shell 
about 4 feet from the bottom plate. From this belt a cast iron 
air box bolted to the shell extends down nearly to the bottom 
plate in front of each tuyere. The front of this box has a slid- 
ing door extending full length of the box. The cupola shell 
has a slot in front of each box the full length of the box. On 
each side of this slot a piece of angle iron is riveted to the shell 
to hold the lining in place. The slot is filled in with fire-brick, 
and a tuyere opening is left at any desired height from the 
bottom. When it is desired to lower the tuyere the bricks are 
removed from the bottom of the tuyere and placed at the top, 
and held in place by a little stiff daubing or clay, and when it 
is desired to raise it, the bricks are removed from the top and 
placed at the bottom when making up the cupola. With the 
Colliau and Whiting style of air belt an adjustable tuyere can 
be arranged in this way at a very moderate cost, and foundry- 
men who think they must have their tuyeres placed high so 
they can make a large casting and only make such a casting 
once or twice a year, can save a great deal of fuel from the bed 
by having their tuyeres arranged in this way. The old plan of 
putting in two or three tuyere holes one above the other, and 
adjusting the tuyeres during the heat by raising the tuyere pipe 
from one to the other, is not practicable with the modern way 
of charging a cupola, and has long since been abandoned. 

BOITOM TUYERE. 

In Fig. 18 is seen the bottom or centre blast tuyere. This 
tuyere, as will be observed, passes up through the bottom of 
the cupola instead of through the sides, and admits the blast 
to the center of the cupola at the same level as the side 
tuyeres. It is not designed to change the nature of the iron 
by forcing the blast through the molten iron in the bottom of 
the cupola, and, in fact, the blast has no more efTect upon the 
quality of iron when admitted in this way than when admitted 
through side tuyeres. A tuyere when placed in the bottom of 
a cupola, unlike a side tuyere, is brought in direct contact 



62 



THE CUPOLA FURNACE. 



with heated fuel and molten iron, and it must be made of a 
refractory material, or protected by a refractory material if 
made of metal. The tuyere shown in the cut is made of cast 
iron and is provided with a water space between the outside 
and the inside, through which a stream of water constantly flows, 
when the tuyere is in use, from a small pipe connected with a 
tank placed alongside the cupola or on the scafTold. But it 
has not been found necessary to Iceep the tu}'ere cool with 
water in short heats, for the heat in a cupola under the tuyeres 




BOTTOM TUYERE. 



is not sufficiently intense to melt cast iron, and the tuyere may 
be sufficiently protected against molten iron dropping upon it 
of coming in contact with it by a thick daubing of refractory 
material held in place by the prickers cast on the tuyere. The 
mouth of a bottom tuyere must be covered to prevent molten 
iron, slag and fuel dropping into it in their descent to the 
bottom of the cupola. This is done with a rounded cap placed 
on top of the tuyere to throw ofif the molten iron and slag, and 
the blast is admitted to the cupola through an opening around 



CUPOLA TUYERES. 63 

the tuyere under the cap, as indicated by the arrows. The 
tuyere must be carefully dried and daubed before it is put in 
place. It cannot be attached to the bottom doors and must be 
put in place through a hole in the doors after they are put up, 
and withdrawn in the same way and removed before the cupola 
is dumped, to prevent it being broken or injured in falling or 
by the heat in the dump. It must have an adjustable and re- 
movable support, and the sand bottom must be made up very 
carefully around it to prevent leakage of molten iron. The 
tuyere often gets fast in the bottom and the men are frequently 
burned in removing it, and it sometimes gets filled with iron or 
slag, and spoils a heat. 

The bottom tuyere has been tried a great many times by 
foundrymen at different periods, and is nothing new. In con- 
versing with several old foundrymen in Massachusetts about 
20 years ago, we learned that the bottom tuyere has been used 
in that State away back in the 40's, and at one time was quite 
popular with foundrymen there ; and we have met a number of 
other old foundrymen in different sections of the country who 
had tried the tuyere years ago and given it up. A bottom 
tuyere was patented by B. H. Hibler in this country August 
13, 1867. Ireland and Voisin used a bottom tuyere in their 
cupolas many years ago, and had these practical men found 
any advantages in it over the side tuyere it would, no doubt, 
have been brought into general use in cupolas before this. 

The bottom tuyere was brought prominently before the 
foundrymen of this country by an ably written article by 
Thomas D. West, read before the Western Foundrymen's 
Association at Chicago, 111., October 18, 1893, in which he 
describes his experiments with the tuyere and claims for it a 
great saving in fuel and cupola lining. Since the publication 
of Mr. West's article a nimiber of foundrymen have published 
their experience with the tuyere and all claim it effects a great 
saving in lining and fuel. But if these foundrymen have not 
discovered some new feature in the tuyere that was overlooked 
by experimenters with it years ago, it will never come into 
general use. 



64 THE CUPOLA FURNACE. 

Since the publication of the above in the first edition of this 
work, the bottom tuyere has been extensively tried by practical 
foundrymen and by cupola manufacturers who have constructed 
a variety of bottom tuyere devices, all of which were designed 
to obviate the difificulty of placing the tuyere in position, main- 
taining it there, removing it after a heat, and preventing molten 
iron and slag getting into it. So far as we have been able 
to learn all of these devices have been failures to so great 
an extent that the use of this tuyere has been practically 
abandoned; very few, if any, of them are being used at the 
present time. 

SIZE OF TUYERES. 

Foundrymen make a great mistake in placing small tuyeres 
in their cupolas, with a view of putting the blast into the 
cupola with greater force and driving it to the center of the 
cupola with the blower. Air may be driven from a small 
opening by a blower with greater velocity than the same vol- 
ume of air from a large opening, but the air from a small 
opening loses its velocity when it strikes a solid body, just the 
same as the air from a large opening. When the blast from a 
small tuyere strikes the solid fuel in front of it, its velocity is 
gone and it will not penetrate any further into the stock than 
the same volume of blast from a large tuyere. It is not the 
velocity at which the blast passes into a cupola that drives it to 
the center, but the force behind the blast. Neither is it the 
velocity of the blast that does the melting. It is the volume of 
blast. It therefore follows that nothing is gained in melting 
by forcing the blast through a small tuyere into a cupola with 
great velocity, and much is lost by increasing the power re- 
quired to run the blower to force the blast through a small 
tuyere. 

The small tuyere was one of the greatest mistakes made in 
the old-fashioned stave cupola. In these cupolas, many of 
which we have seen, only two tuyeres of 3 or 4 inches diameter 
were placed in a 30-inch cupola, and the improvement made in 



CUPOLA TUYERES. ^ 65 

melting in the modern cupola is largely due to the enlarge- 
ment of the tuyeres and the free admission of blast to the 
cupola. 

The combined tuyere area of a cupola should be equal to 
three times the area of the outlet of the blower when the 
blower is of a proper size for the cupola. These dimensions 
may at first sight seem large, but it must be remembered that 
the size or area of a tuyere when a cupola is not in blast does 
not represent the area of the tuyere when a cupola is in blast, 
or the volume of blast that may be admitted to the cupola by 
the tuyere. When a cupola is in blast the space in front of 
the tuyere is filled with fuel weighted down with tons of iron. 
This fuel closes the mouth of the tuyere, and the outlet is rep- 
resented by the number of crevices between the pieces of fuel 
through which the blast may escape. Should a large piece of 
fuel fall in front of a tuyere the blast cannot remove it and the 
tuyere may be closed and rendered useless. Small tuyeres 
are more liable to be closed in this way than large ones, and 
for this reason they should never be placed in a cupola. Small 
tuyeres, furthermore, are not only more liable to be stopped ofT 
by the fuel, but also tend to promote bridging by admitting an 
insufficient amount of blast at certain points. 

HEIGHT OF TUYERE. 

There is a wide difference of opinion among foundrymen as 
to the height or distance tuyeres should be placed in a cupola 
above the sand bottom. So great is this difference of opinion 
at the present time that tuyeres are placed in cupolas at from 
2 inches to 5 feet above the sand bottom. This wide variation 
in the height of tuyeres is due to some extent to the different 
classes of work done in different foundries, it being claimed by 
foundrymen making heavy work that it is necessary to have 
the tuyeres high to hold molten iron in the cupola and keep it 
hot for a large casting. Foundrymen making light castings 
requiring very hot iron draw the iron as fast as melted, and do 
not think it necessary to have high tuyeres to hold iron in the 

5 



66 THE CUPOLA FURNACE. 

cupola. In the many experiments we have made in melting 
iron in a cupola, we have placed the tuyeres at various distances 
above the sand bottom, and closely observed the effect of 
them at different heights. We learned by these experiments 
that the fuel under the tuyeres it not consumed in melting, 
nor is it wasted away to any extent by the heat or molten iron 
coming in contact with it. Charcoal may be placed in the 
bottom of a cupola, and if care is taken to prevent its being 
consumed by admission of air through the front before the 
blast is put on, the charcoal will not be consumed during the 
heat and may be found in the dump. We have tried this in our 
experiments to soften hard iron by bringing the molten metal 
in contact with charcoal in the bottom of a cupola, and found 
it correct. Pieces of charred wood used in lighting up are 
often found in the dump after having remained in the cupola 
throughout a heat. If these soft combustible substances are not 
consumed under the tuyeres, then it is not at all likely that the 
less combustible hard coal and coke are consumed. No iron 
can be melted in a cupola under the tuyeres, and the only 
function of the fuel below the tuyeres is to support the stock 
in a cupola above the tuyeres. If there is not sufficient heat 
in the bottom of a cupola to consume wood or charcoal, then 
there is not sufficient heat to keep molten iron hot for any 
length of time ; and it is a well-known fact among practical 
foundrymen that large bodies of molten iron can be kept hot 
and fluid for a greater length of time in a ladle when covered 
with charcoal to exclude the air than they can be in a cupola. 

Another reason given in favor of high tuyeres is that it is 
necessary to have them high to tap slag in long heats. The 
only slag in a cupola that can be drawn through a slag hole is 
a light fluid slag and floats on top of the molten iron or rests 
on the bottom of the cupola when there is no molten iron in 
it, and this slag may be drawn at any point between the sand 
bottom and tuyere. When a slag hole is placed high, slag 
only can be drawn when the cupola is permitted to fill up with 
molten iron and raise the slag upon its surface to the slag hole. 



CUPOLA TUYERES. 67 

Slag may then be drawn for a few minutes while the cupola is 
filling up with iron to the slag hole. As soon as the iron 
reaches the slag hole, however, it flows out and must be tapped 
from the front. This slag then falls in the cupola with the sur- 
face of the iron as it is drawn ofT, and the slag hole must be 
closed to prevent the escape of blast through it. Iron tapped 
after permitting a cupola to fill up to a high slag hole is always 
dull. 

When a slag hole is placed low it is not necessary to have 
the cupola fill up with iron before slag can be tapped, for the 
slag may be drawn ofif the bottom of the cupola, and, further- 
more, the slag hole may be opened and permitted to remain 
open throughout a heat without waste of blast. The flow of slag 
regulates itself when the hole is of proper size. It is, there- 
fore, not necessary to place tuyeres high that slag may be 
drawn from a cupola, nor is it necessary to hold iron in a 
cupola for a large casting or to keep it hot. Molten iron 
should be handled in a ladle and not in a cupola. 

Hot iron for light work cannot be made in cupolas with high 
tuyeres, and for this reason the tuyeres in stove-foundry cupo- 
las are always placed low. In cupolas of large diameter, hav- 
ing a large bottom surface for molten iron, the tuyeres are 
placed so low that those at the back of the cupola are not 
more than i inch above the sand bottom, and those in front 
not more than 2 or 2J^ inches above the sand bottom. 
Tuyeres placed in this way give ample space below them to 
hold molten iron for this kind of work, for the iron must be 
very hot and is drawn from the cupola as fast as melted, and 
the cupola is large enough to melt iron as fast as it can be 
handled, and it is only when the cupola is not working free 
that it is stopped up to accumulate iron. The tuyeres in any 
cupola may be placed as low as in these large ones, if provision 
be made for handling the iron as fast as melted. 

In smaller cupolas not capable of melting iron sufficiently 
fast to fill a 40-pound hand-ladle, every 8 or 10 seconds the 
tuyeres are placed from 2 to 4 inches above the sand bottom, 



6S THE CUPOLA FURNACE. 

SO that a sufficient quantity of iron may be collected before 
tapping to give each man in the section catching a hand-ladle 
full, and fill the ladle in about 6 seconds. 

In cupolas of very small diameter the tuyeres should be 
placed from 6 to lO inches above the sand bottom. These very 
small cupolas melt so slow that if the iron is drawn as fast as- 
melted the stream is so small that the iron is chilled in flowing: 
from the cupola to the ladle more than it is by holding it in. 
the cupola until a body of iron is collected sufficient to supply 
a large stream. 

In machine and jobbing foundry cupolas tuyeres are gen- 
erally placed from i8 to 24 inches above the sand bottom^ 
The object in placing the tuyeres so high is to hold iron in the 
cupola for a large casting. But, as before explained, this is not 
necessary or advisable. Another reason for these high tuyeres 
IS that they are necessary for tapping slag. The slag from 
many cupolas is drawn off at the tap hole with the iron, and a 
number of spouts have been invented for separating the slag: 
from the iron and preventing it running into the ladle. Slag 
may be drawn from the back of a cupola on a level with the 
sand bottom at that point, if the iron is drawn as fast as melted^ 
or it may be drawn i, 2 or more inches above the sand bottom 
at that point. It is, therefore, not necessary to place tuyeres 
at so great a height to tap slag. 

The tuyeres in cupolas for heavy work should be placed 
from 6 to 8 inches above the sand bottom when slag is not to 
be tapped. This gives an abundance of room in a cupola for 
"holding iron while removing or placing a large ladle, and that 
is all that is necessary. The tuyeres in many of the cupolas 
used in Bessemer steel works are placed five feet above the 
bottom. They are probably placed at so great a height be- 
cause the tuyeres in the first cupola constructed for this work 
were placed at that height. Tuyeres in all cupolas should be 
placed as low as they can be for the size of the cupola and 
facilities for handling the iron, for the fuel placed in a cupola 
under the tuyeres is not consumed in melting and is wasted by 



CUPOLA TUYERES. 69 

being heated in the cupola and crushed and burned in the 
dump. The vakie of fuel wasted every year in the United 
States by the use of high tuyeres in cupolas is sufficient to 
make a man rich. 

NUMBER OF TUYERES. 

A cupola may be supplied with blast from one tuyere placed 
on one side of the cupola, but the objection to one tuyere 
arranged in this way is that the heat is driven by the blast 
against the opposite side of the cupola, and the destruction of 
lining at this point is very great. For this reason, at least two 
tuyeres are always placed in a cupola, and they are located on 
opposite sides so that the blast will meet in the center and be 
diffused throughout the stock. When a greater number of 
tuyeres than two are placed in a cupola they are located opposite 
•each other and at equal distances apart, to admit an equal 
amount of blast on all sides and prevent an uneven destruction of 
lining from the heat being forced unevenly against it by the 
blast. Any number of tuyeres desired may be placed in a 
cupola, and as high as 100 have been used in a 40-inch cupola, 
and a greater number in larger cupolas. But these large num- 
bers have given no better results in melting than two or four 
tuyeres in the same cupolas. It is not necessary to place a 
large number of small tuyeres in a cupola to distribute the blast 
€venly to the bed, and it is not advisable to put in small tuyeres, 
which are easily closed by the fuel, cinder and iron, and are 
oftener rendered useless than large ones. Better results are 
obtained from large tuyeres and fewer of them. 

The largest cupola in use may be supplied with blast by two 
tuyeres if they are big enough. The large cupola of the 
Buffalo School Furniture Company, Buffalo, N. Y., is supplied 
with blast by two tuyeres 12x18 inches, placed on opposite 
sides. The cupola, which is 60 inches in diameter inside, does 
excellent melting with only these two tuyeres, and the destruc- 
tion of hning in melting is very light. We saw a large cupola 
with two tuyeres of about the above dimensions in use in a 



70 THE CUPOLA FURNACE. 

Stove foundry in St. Louis, Mo., about 20 years ago, and it 
did excellent melting. The results obtained from these two 
cupolas would go to show that there is nothing gained in dis- 
tributing the blast to the bed evenly by a large number of 
small tuyeres. When a number of tuyeres are placed in one 
row, every other tuyere is sometimes placed about the width 
of the tuyeres higher than those on either side of it. We 
have, however, never observed that anything was gained in 
melting by placing tuyeres in this way. When a double row 
of them is used the upper row should be made very small in 
comparison with the lower row, for if they are made of the 
same size as the lower one, or even half the size, and the two 
rows are placed at any great distance apart, the heat is so con- 
centrated upon the lining between them that it may be burned 
out to the casing in one or two heats. Foundrymen using the 
double tuyeres, who find the destruction of lining very great, 
may prevent it to some extent by reducing the size of the 
upper tuyeres. 

SHAPE OF TUYERES. 

The shape of a tuyere has nothing to do with the melting, 
except as it may tend to prevent bridging or increase the depth 
of the melting zone by supplying blast to the fuel at different 
heights in a cupola. A small horizontal slot tuyere extending 
around a cupola, or the greater part of the way around it, tends 
to promote bridging, and it is generally conceded that a cupola 
with a tuyere of this kind cannot be run for a greater length of 
time than two hours without bridging and clogging up. Vertical 
slot and reducing tuyeres supply blast to the bed at different 
levels and increase the depth of the melting zone the same as 
the double tuyere. For this purpose the Truesdale, Lawrence 
and triangular tuyeres, with elongated sides, are excellent when 
made of a proper size and placed a proper distance apart. 
When it is not desired to admit the blast to the bed at different 
levels, the flat or oval tuyeres are generally considered the best 
shapes, for they admit the blast freely, and a less amount of 



CUPOLA TUYERES. J I 

fuel is required for a bed with these shapes than with a round 
or square tuyere of the same area. 

TUYERES TO IMPROVE THE QUALITY OF IRON. 

All kinds of fancy shaped tuyeres have been placed in 
cupolas to improve or change the quality of iron in melting. 
They have been placed to point up, point down, point across 
each other at certain angles, and to point to the centre of the 
cupola. There is nothing more absurd than to attempt to 
improve the quality of iron in a cupola by the shape or angle 
of the tuyers. The instant the blast leaves the mouth of a 
tuyere it strikes the fuel in front of it. The shape or angle 
given to it by the tuyere is then instantly changed, and it passes 
through the crevices in the fuel until its oxygen enters into 
combination with the carbon of the fuel and produces combus- 
tion. It then escapes at the top of the melting zone, where it 
comes in contact with the iron as carbonic acid gas. This is 
the result, no matter what the shape or angle of the tuyeres, if 
a proper amount of blast is supplied. It may be claimed that 
the blast acts upon the iron as it drops through the fuel in the 
bed after being melted ; but as before stated, the shape or 
angle given to the blast by the tuyeres is changed by the fuel, 
and the effect on the iron of the blast from one tuyere would 
be the same as from another. 

TUYERE BOXES. 

The tuyeres may be and are often formed in the lining of a 
cupola when laying the brick, but this is a very poor way of 
making tuyeres, for there is nothing to support the brick and 
maintain the shape of the tuyeres, and they are often broken 
or burned away until there is no regular shape to the aperture,, 
and it is difficult to put the blast into the cupola at the point 
desired or to prevent iron or slag getting into the tuyere. Tuy- 
eres are more generally formed with a cast iron. lining or tuyere 
box, having the shape and size of tuyere desired. This box 
may be cast with a flange on one end and be bolted to the cas- 



72 THE CUPOLA FURNACE. 

ing, or it may be cast without a flange and placed in the lining 
at the desired point as it is laid up. The boxes are made in both 
ways, but it is better to cast them with a flange and bolt them 
to the casing, making an air-tight joint, as it then insures the 
blast going directly into the cupola at the point desired. Tuyere 
boxes laid in a lining answer the purpose very well when the 
lining is new, but when it becomes old and shaky, or a section 
is removed and replaced, the lining often settles and the grout- 
ing or filling falls out, leaving crevices through which the blast 
escapes between the casing and lining, and from there enters 
the cupola at points where it does no good. 

The cold blast supplied to a cupola keeps the tuyere box 
cool, and it is not necessary to cast it hollow and fill it with 
water to prevent it being melted or injured by the heat. The 
only part of the box that is exposed and liable to be injured 
is the end next the fire, and to protect it the box at this point 
is generally cast about yi inch shorter than the thickness of 
the lining and the end covered with a little clay or daubing. 

NEW TUYERES. 

Since the publication of the second edition of this work, three 
new designs of tuyeres have been patented and installed in 
cupolas with marked improvement in melting in some cases 
and complete failure in others. The success in some instances, 
and failure in others, was in many cases no doubt due to the 
dififerent pressures or volume of blast furnished the cupola. 
But in other cases it was doubtless due to the patentee mak- 
ing too extravagant claims for his tuyere in the saving of 
fuel, fast melting, clean drop, etc., results he was not able to 
demonstrate, in well managed cupolas. Tuyeres are not the 
only factor in successful cupola practice, and for this reason the 
enthusiastic new tuyere patentee or designer should learn what 
results are being obtained from the cupola and compare them 
with results he has obtained in other cupolas, and if the com- 
parison does not show a chance for a decided improvement in 
favor of his tuyere, he will save himself considerable time and 



CUPOLA TUYERES. 



73 



money by not placing it in the cupola. The same policy 
should be followed by the founder to insure him against loss 
from bad heals that are almost certain to result in case of 
failure. 



THE WAIT CUTOLA TUYERES. 



The Watt cupola tuyere was designed by Mr. Watt, founder 
of the Watt Mining Car Wheel Company of Barnesville, Ohio, 
for use in the cupolas of their plant, and it gave such excellent 
results in melting and clean drop that Mr. Watt was induced to 
obtain a patent on the tuyere and formed The Watt Cupola 
Tuyere Co., to place the tuyere upon the market. This tuyere, 
as will be seen in the illustration. Fig. 19, is a belt tuyere ex- 



FiG. 19. 



Fig. 20. 





tending around the cupola, the front of which is covered with 
lattice-work plates, thus presenting an entirely new feature in 
tuyere construction. The other illustrations show the various 
parts used in the tuyere. Fig. 20 represents the belt air 
chamber, which is cast in sections and placed inside the cupola 
shell in the lining. Openings are provided in the backs of these 
sections for admissions of blast from the outside belt air 
chamber of the cupola to the inner chamber, and the size of 
tuyeres for cupolas of various diameters are regulated by the 
depth or width of this air chamber. Fig. 21 shows a section 



74 



THE CUPOLA FURNACE. 



Vv^ith tuyere plates attached so as to come flushed with the 
cupola lining. Fig. 22 shows the tuyere plates with hooks cast 
upon them for attaching to the air chamber and admitting of 
their removal in case iron or slag gets into the tuyere. This 



Fig. 21. 




tuyere, which gave every promise of success from the excellent 
results obtained in the Watt plant, was placed by The Watt 
Cupola Tuyere Co. in many cupolas throughout the country 
with excellent results in melting in many cases, but in others 
it failed to give even as good results as that obtained from 
the one which it replaced. This was no doubt due to the 
outlet area of the tuyere being much greater than that of the 
one it replaced and, the volume of blast not being sufiticient 

FiGr 22. 





to supply the tuyere with air for an equal distribution. Fail- 
ures was also no doubt due in some instances to too great a 
claim being made for the tuyere in saving of fuel hot iron, fast 
melting, etc. ; a mistake frequently made by tuyere designers. 



CUPOLA TUYERES. 75 

IHE ZIPPLER TUYERE. 

In Fig. 23 is shown the Zippier tuyere. This tuyere was 
designed by the late Michael Zippier, an old melter of Pitts- 
burg, Pa., and installed in a number of cupolas 25 to 30 years 
ago with good results in many cases. But the shape of lining 
required for the tuyere was difficult to maintain, and the tuyere 
never came into general use. A few years ago Mr. Zippier 
improved it by adding a second row of tuyeres and the 

Fi<;. 2.^ 




THE ZIPl'LER TUYKRE. 



use of metal blocks around the tuyeres, which supported the 
over-hanging lining and made it more stable and readily 
maintained in its original shape. Since this improvement, for 
which he obtained a patent, the tuyere has been installed in a 
number of large cupolas with excellent results. But, like all 
others, it has failed in a number of instances to produce hotter 
iron or do faster or more economical melting than the one in 
use before its installation. 



THE KNOEPPEL TUYERE. 



In Fig. 24 may be seen the Knoeppel system of cupola 
tuyeres, designed and patented by John C. Knoeppel, a prac- 
tical foundryman of Buffalo, N. Y. The tuyeres embrace the 



76 



THE CUPOLA FURNACE. 



same principles as the Zippier tuyere, namely the overhanging 
bosh, and only differs from it in a third row being added 
and the upper rows being made smaller than the Zippier. 
This tuyere has been installed in a number of large cupolas 
with marked improvement in melting and saving of fuel, and is 
an excellent tuyere for large cupolas in which it is desired to 
hold molten iron. Neither of these tuyeres present any new 

Vh,. 24. 




THE KNOEPPEL TUYERE. 



features in cupola construction or tuyere arrangement for, as 
will be seen by reference to Fig. 64, the overhanging bosh and 
double row of tuyeres were designed and patented by Mr. 
Ireland, an English cupola inventor in 1856, and the over- 
hanging bosh may also be seen in the illustration of a number 
of other English cupolas in use about that time. But this 
feature was abandoned later on, and cupolas were constructed 
with straight linings, or boshed from the bottom plate to the 
desired height above the tuyeres. 



CHAPTER V. 

CUPOLA MANAGEMENT. 

The peculiarities in the working of every cupola must be 
learned before it can be run successfully, and this can only be 
done by working it in different ways. It is a question very 
much disputed whether a cupola constructed upon the latest 
improved or patented design is superior to one of the old style. 
This question can only be decided by the intelligent working 
of each cupola, and the advantage will always be found in favor 
of the one that is properly worked, no matter what its con- 
struction. It is the duty of every foundryman to give his per- 
sonal attention to the working of his cupola if he has time. If 
he is not a practical founder or has not the time to devote to 
this branch of the business that it requires, then he should have 
his foundry foreman give it his personal attention for a sufficient 
length of time each day to see that everything is right in and 
about the cupola. 

No cupola can be run successfully by any given rule or set 
of rules, for conditions arise to which the rules do not apply. 
We shall therefore not only give directions for the proper 
working of a cupola at every point, but shall also give the re- 
sults or effect of bad working at every point, so that the founder 
when he finds his cupola is not operating well may have some 
data from which to draw conclusions and be able to overcome 
the difficulty. 

DRYING THE LINING. 

The cupola having been newly lined, nothing is to be done 
to the lining for the first heat but to dry it. A very high or 
prolonged heat is not required for this when only one thick- 
ness of brick is put in and laid up in thin grout. The lining 

{77) 



78 THE CUPOLA FURNACE. 

may be dried by making a wood fire after the sand bottom is 
put in, or by starting the fire for the heat a little sooner than 
usual. But the fire must not be started too early or the bed 
will be burned too much and the cupola filled with ashes, which 
will retard the melting. 

When a backing or filling of wet clay or sand several inches 
thick is put in between the casing and lining, more time and 
care are required in drying. It must then be dried slowly and 
evenly, or the filling will crack, and when jarred in chipping 
out will crumble and work out through cracks in the lining or 
holes in the casing and leave cavities behind the lining. When 
a lining is put in in this way, the doors are put up and covered 
with sand and a good coal or coke fire is made in the cupola 
and allowed to remain in over night. In the morning the 
bottom is dropped to remove the ashes and cool ofif the lining 
before making up the sand bottom for a heat. 

PUrriNG UP THE DOORS. 

The first thing to be done when making up the cupola for a 
heat is to put up the bottom doors. When the cupola is of 
small diameter and the door light, it may be raised into place 
and supported by one man. But when the door is heavy two 
men are required, aud if the cupola is a large one and the door 
made in two parts, three men are required to lift and support 
them. Two men get inside the cupola and raise one-half into 
place while the third man supports it with a temporary prop ; 
they then raise the other half as far as it can be raised with 
their bodies between the two doors, where it is supported by a 
temporary prop. The men then get under the door on their 
hands and knees and raise it into place on their backs, and it 
is then supported by a prop. 

Numerous devices have been arranged for raising the doors 
into place, but they soon get out of order from the heat of the 
dump or carelessness in manipulation, and they have almost all 
been abandoned. When the cupola is very small and the door 
light, it is sometimes supported by an iron bolt attached to the 



CUPOLA MANAGEMENT. 79 

under side of the bottom plate at the front, where it can be 
readily withdrawn with an iron hook to drop the bottom. But 
the doors are generally supported by a stout iron prop or post 
placed under the door near the edge opposite the hinges. 
Double doors are supported by a stout iron prop in the center 
and generally a light one at each end of the doors to prevent 
them springing when charging the fuel and iron, or by a sudden 
settling of the stock, as may occur when melting large chunks. 
A great many melters have no permanent foundation under the 
cupola upon which to place the main prop, but make one every 
heat by laying down a small plate upon the sand and setting 
the prop upon it. The plate is often placed too high or too 
low, making the prop too long or too short, and the plate must 
be raised by putting a little more sand under it or lowered by 
scraping away a little sand. When this is being done the 
heavy iron prop, which frequently requires two men to handle 
in the cramped position in which they are placed under the 
cupola, has often to be put up and taken down two or three 
times before it is gotten into the right position to support the 
doors. 

All this extra labor can be avoided and time saved by im- 
bedding a heavy cast-iron block in the floor or foundation 
under the cupola for the prop to rest upon. It must extend 
down a sufficient distance to insure its not being disturbed when 
shoveling out the dump. A block 6 inches square and 10 
inches long, placed with the end level with the floor, will seldom 
be displaced, and makes a sure foundation for the prop. The 
size of prop required to support a bottom depends upon the 
size of cupola. In small cupolas the stock is supported to a 
large extent by pressure against the lining, while in large 
cupolas the stock is supported almost entirely by the prop. 
For small cupolas the props are made from i ^ to 2 inches 
diameter, and for large cupolas from 3 to 3^ inches diameter. 

The props for large cupolas not only have a greater weight 
to support, but they are seldom pulled out of the dump and 
are therefore, if light, liable to be bent and twisted to such an 



8o THE CUPOLA FURNACE. 

extent as to render them useless. For this reason they are 
often made heavier than is actually necessary for the support 
of the bottom. Quite a number of foundrymen have adopted 
the plan of attaching a ring to the prop near the top or bottom 
with which to draw it from the dump and avoid heating it. The 
ring is made large and hangs loosely, or as a long loop which 
stands out from the prop. When the prop is to be removed a 
hook is placed in the ring or loop and a quick jerk given, 
which releases it, and it is at once drawn from under the 
cupola. 

Some of the older melters never use the iron prop, but 
measure and cut a new wood prop for their cupola every heat. 
Many of them are so superstitious that they think the cupola 
would not melt without the new prop, and they would rather 
give up their jobs than try it. Such melters are not so plenti- 
ful now as they were 30 years ago, when we first began travel- 
ing as a melter through this country and Canada, but we find 
when visiting foundries there are still a few of them left. 

DROPPING THE DOORS. 

When it is desired to drop the doors it is done by removing 
the props or drawing the bolt. The small props are first taken 
out, being released by a stroke of the hammer, and are care- 
fully laid away so that they will not be bent by the heat of the 
dump. A long bar with a handle on one end and a large hook 
on the other is then placed under the cupola with the hook be- 
hind the main prop and about 10 or 12 inches from it. By a 
sudden jerk of the bar the hook is made to strike the bottom 
of the prop a sufficiently hard blow to knock it out of place 
and permit the door or doors to drop. Two or more blows of 
the bar are sometimes necessary to release the prop, but it can 
always be released in this way. It can also be released by 
striking it at the top with a straight bar, but it is oftener 
missed than hit, and many thrusts are sometimes required to 
bring it down. Bolts are only used on small cupolas from 
which the dump falls slowly, and the bolt can generally be with- 



CUPOLA MANAGEMENT. 8 I 

drawn by a blow of the hammer without danger to the melter. 
If it cannot be withdrawn in this way without danger of burn- 
ing the melter, a hook is made on the end of the bolt or a ring 
placed in it so that it may be drawn with a hooked bar or 
struck with a long straight bar. 

SAND BOTTOM. 

When the door or doors are in place and properly sup- 
ported, any openings or holes that may have been burned 
through them are carefully covered with a thin plate of iron, 
and all cracks through which the bottom sand might escape 
when dry are closed with clay. The doors are then covered 
with a bed of sand several inches in thickness, which is known 
as the sand bottom. The sand employed for this purpose 
must not be of a quality that will burn away and permit the 
molten iron to get down to the doors, or melt and form a hard 
mass that will not fall from the cupola when the doors are 
dropped, neither must it be so friable as to permit the molten 
iron to run through it when dry. 

The clay sands when used for a bottom burn into a hard, 
tough mass that adheres to the lining all around the- cupola, 
and in a small cupola frequently remains in place after the door 
is dropped and has to be dug out with a bar before the cupola 
can be dumped. Parting sand, sharp and fire sands are very 
friable and difficult to keep in place. They do not resist the 
action of the molten iron well, but melt and form a slag. 
Mixtures of clay and sharp sand burn too hard and do not drop 
well. The loam sands are the only ones suitable for a sand 
bottom, and sand that has been burned to a limited extent 
makes a better bottom than new sand. 

In stove and other foundries with large gangway floors the 
scrapings from the gangways are collected in front of the" 
cupola, passed through a No. 2 riddle to recover the scrap 
iron, and the sand used for the cupola bottom. This sand 
makes the very best kind of bottom. It is clean and free from 
cinder, soft and pliable, packs close, resists the action of the 
6 



82 THE CUPOLA FURNACE. 

molten iron and drops free. In foundries where the daily 
gangway cleanings are not sufficient to make the bottom, part 
of the old bottom is used over and the gangway cleanings are 
mixed with it or placed on top. In foundries where there are 
no regular gangways to clean every day, the heavy part of the 
dump is thrown out and the sand bottom passed through a No. 
2 riddle and used over again. When the bottom sand is used 
over day after day, it must not be riddled out too close, and a 
little fresh material must be added to it each day to prevent it 
from becoming rotten from repeated burnings and containing 
too many small particles of cinder, which render it fusible and 
easily cut away by the molten iron. The cleanings from the 
moulding floors are generally added or a few shovelfuls from 
the sand heaps, and in case it becomes too rotten a few shovel- 
fuls of new moulding sand are mixed with it. 

When the material contains so much cinder that it does not 
make a smooth bottom, a few shovelfuls of burned sand from 
the heaps are put on to give an even surface and prevent the 
molten iron from coming in contact with the cinder and cutting 
the bottom. The bottom sand is generally wet with water, but 
some melters wet it with clay wash, to make it more adhesive 
and give it more strength to resist the action of the molten 
iron. A thick clay wash gives strength to a rotten sand when 
mixed with it, but it also increases the tendency of the bottom 
to cake and hang up, and it is better to improve the bottom 
material in the way above described and wet it with water 
only. The sand when wet is cut over and evenly tempered, 
and should be no wetter than moulding sand when tempered for 
a mould. 

The sand may be thrown into the cupola through the front 
opening, or may be thrown in at the charging door, but it is 
generally thrown in at the front, for it is more convenient to 
the material, and is also convenient for spreading it in the 
cupola. When the cupola is small the melter stands by the 
side of it and makes up the bottom by passing his arm in 
through the front opening; but when the cupola is large he 



CUPOLA MANAGEMENT. 83 

goes inside, and his helper shovels the sand in as he wants it. 
The first sand thrown in is carefully packed around the edges 
with the hands to insure a tight joint. As the balance of the 
sand is thrown in, it is spread evenly over the bottom in layers 
from I to 2 inches thick, and each layer is evenly rammed or 
trampled down until the required thickness of bottom is 
obtained, which is from 3 to 6 inches, according to the rise of 
the cupola. The desired pitch or slope for throwing the iron 
to the front is then given, and the bottom butted evenly and 
smoothly all over. The melter next goes carefully around the 
edges with his hands and feels for any soft spots there may be 
near the lining, and slightly raises the edges of the bottom 
around the lining to throw the iron ofT and prevent it from work- 
ing its way down between the lining and sand bottom. The 
bottom is then carefully brushed and smoothed off, and in 
small cupolas a bucketful of thin clay wash is sometimes thrown 
in at the front and caught in the bucket as it runs out. This is 
called slushing the bottom, and is done to give a smooth, hard 
surface. 

The sand bottom does not always remain impervious to the 
molten metal, but is sometimes penetrated or cut up and de- 
stroyed by it, in which case a leakage of molten iron takes 
place from the bottom of the cupola that is difficult to stop. 
Leakage of this kind may be due to springing of the bottom 
doors when charging and the cracking or loosening of the sand 
bottom around the lining. This can be prevented by placing 
more props under the doors to support them. Sand that has 
been used over and over in a bottom until it has become worn 
out and filled with cinder is readily cut up and converted into 
a slag by the molten iron, and it is only a question of the time 
occupied in running off the heat whether the bottom gives 
way or stands. When the bottom sand gets into this condi- 
tion, it must be renewed by the addition of new sand, or the 
bottom covered with a layer of sand from the moulders' sand 
heaps. 

Molten iron will not lie upon a wet, hard substance, but will 



84 THE CUPOLA FURNACE. 

explode or boil and cut up such material upon which it is placed. 
If the bottom sand is made too wet, or rammed too hard, or 
rammed unevenly, the iron will not lie upon it, but will boil 
and cut up the sand until it gets down to the doors, which it 
will melt, and run through. When a bottom cuts through, 
melters frequently attribute it to the bottom being too soft ; 
and we have seen them take a heavy pounder and ram a 
bottom as hard as a stone. In these cases, if the sand was 
worked very dry, or the bottom was well dried out before any 
molten iron came in contact with it, it did not cut up or leak; 
but if the sand was wet when the molten iron came down, boil- 
ing at once took place and the bottom soon cut through — and 
in such cases they generally cut through about every other 
day. In the sand bottom of a cupola we have the same ele- 
ments to contend with, so far as molten iron is concerned, as 
we have in a mould ; and the sand should be worked no wetter, 
rammed no harder, and rammed as evenly as the sand for a 
mould. The sand should not be worked wet for a bottom, under 
the impression that it is dried out before the iron comes down, 
for the ashes of the shavings, wood, coal or coke cover the 
bottom soon after the fire is started, and protect it from the 
heat to such an extent that it is only dried to a very limited 
degree before the iron comes down upon it. Water may be 
seen dripping from a very wet bottom long after the blast is 
on. Even if it were dried out, wet sand cracks when dried 
rapidly and should not be used. We shall not attempt to give 
any directions for stopping a leak after it occurs, for the time 
and place to stop a leak is when putting in the sand bottom ; 
and if all the remedies we have given for preventing leaks fail, 
then it is time to change the melter. 

The pitch or slope given to the bottom to cause the molten 
iron to flow to the tap hole from all parts of the bottom has a 
great deal to do with the temperature of the iron and nice 
working of a cupola. When the bottom is made too low and 
flat, molten iron lies in the bottom of the cupola and becomes 
dull. As the melted iron falls into this iron drop by drop, it is 



CUPOLA MANAGEMENT. 85 

instantly chilled and the iron when drawn from the cupola is 
dull. This effect is more marked in a cupola melting very 
slowly, and a low bottom may be the cause of very dull iron 
when a sufftcient quantity of fuel is consumed to make very 
hot iron. A high pitch throws the iron from the tap hole with 
great force and spouting velocity, and it is almost impossible 
to run a continuous stream from a cupola with such a bottom. 
It is more dif^cult to keep the tap hole and spout in order, and 
the stream must be closely watched to prevent it shooting over 
the ladle and burning the men. Slag flows freely from the tap 
hole with the stream of iron when the bottom has a high pitch, 
even when there is very little slag in the cupola. But the flow 
of slag from the tap hole with the iron may be entirely stopped 
by changing the pitch of the bottom, no matter how great the 
quantity of slag in the cupola. The action of the iron at the 
spout is entirely changed by the pitch of the bottom. A hard 
iron may be made to run smooth from the spout, while a soft 
iron may be made to sparkle and fly, giving all the indications 
of a hard iron. The best expert on the quality of iron at the 
spout may be deceived in the iron by the pitch of the bottom, 
and it is only in the extremely hard and extremely soft irons 
they cannot be deceived. The bottom should never be made 
hollow in the center and high all around the outside with an 
outlet or trough to the spout. This concentrates the iron in 
the center in such a way that a few hundredweights place as 
great a pressure upon the front as a ton would do if the bottom 
were flat, and the front may therefore be forced out by a com- 
paratively small body of iron. The instant the tap hole is open 
the iron rushes out with great force, and it is almost impossible 
to stop it as long as there is any molten iron in the cupola. 

The bottom should be made flat and level from side to side 
with only a slight rise around the lining, which should not ex- 
tend out more than i or 2 inches from the lining. The pitch 
from back to front should not be more than ^ to ^ inch to 
the foot. This has been found to be a sufficient slope to throw 
all the iron to the front in an ordinary cupola. But in cupolas 



<S0 THE CUPOLA FURNACE. 

that melt very slowly a little more slope may be given, so as to 
concentrate the iron more rapidly and prevent it chilling on 
the bottom. 

In cupolas with two tap holes the bottom must be sloped so 
that all the melted iron in the cupola can be drawn from either 
tap hole. It is very difficult for a melter to see what slope he 
is giving a bottom when mside the cupola, and for this reason 
many of them seldom get the slope two days alike. The 
melter should be provided with a notched stick or some other 
gauge, for measuring down from the top or bottom of each 
tuyere, to serve as a guide in sloping the bottom, so that it may 
be given the proper pitch and put in alike every heat. 

SPOUT. 

The old way of making a cupola spout is to place a short 
piece of pig iron on the bottom plate on each side of the front, 
and build up a spout between them with clay or loam. The 
modern spouts are made of cast iron with a flat or eight-square 
bottom, and are from 4 to 6 inches deep, 7 to 10 inches wide 
and I to 10 feet long. They are given a fall from the cupola 
of about I inch to the lineal foot, and are lined with a refractory 
material to protect them from the molten iron. The spout 
lining is made of a different material from the sand bottom, and 
generally consists of molding sand, loam, or a mixture of fire 
clay and sharp sand. Some of the molding sands make an 
excellent spout lining that is not cut or fused by the stream of 
molten iron, while others crumble and break up too readily 
when cleaning the spout of dross and dirt, and cannot be used 
for this purpose. When a molding sand can be used it makes 
a nice clean spout that is easily and quickly made up. It is 
readily dried, and when making up the spout the crust of the 
old lining can be removed with a bar, and the sand wet up and 
used over with a coating of sand without removing it from the 
spout. For long spouts, requiring a good deal of material to 
line them, molding sand is the most economical material that 
can be used. 



CUPOLA MANAGEMENT. 8/ 

Some of the loam and blue clays make excellent spout 
linings alone or when mixed with sand, and are the only 
materials used for this purpose in some sections of the country 
where they can be procured at a moderate cost. They make 
a stronger lining than molding sand — that is, not so liable to be 
broken up when cleaning the spout of dross and slag — and, 
furthermore, they dry quickly. The lining material probably 
more extensively used than any other is a mixture of fire clay 
and sharp sand. These two refractory substances when com- 
bined in right proportions and thoroughly mixed make one of 
the very best spout linings. But when not properly mixed 
they make one of the poorest linings. 

When too much clay is used the lining does not give up the 
water of combination until heated to a very high heat, and it is 
almost impossible to get the lining dry so that the iron will not 
boil in the spout the first few taps, when the spout is long, or 
sputter and fly when it is short. It cracks when dried rapidly, 
and is melted into a tough slag that bungs up the spout and 
cannot be removed without destroying the lining. When too 
much sand is used the lining crumbles when touched with the 
bar and is cut and melted by the stream. When the clay and 
sand are not thoroughly mixed the lining crumbles and cuts or 
melts in spots. A spout lining made of these two materials 
in right proportions, properly mixed and dried, becomes as 
refractory as a fire-brick, and 50 or 100 tons of iron may be 
run from a spout lined with them without a break in the lining. 
There are a number of other materials used for spout linings 
that are only found in certain localities, and their use is re- 
stricted to the districts where they can be procured at a 
moderate cost. But those above described are the materials 
most commonly used for this purpose. 

The spout lining is made up new every heat, and when 
putting it in the spout is wet to make it adhere to it. The 
sand bottom is cut away from the front and the spout lining 
made to extend into the cupola past the tap hole. A perfect 
joint is made between the sand bottom and spout lining, and a 



88 THE CUPOLA FURNACE. 

little clay wash is generally brushed over the joint to make it 
more perfect and prevent cutting. Care must be taken to not 
get the bottom of the spout at the tap hole higher than the 
sand bottom, and also to give it the same pitch as the sand 
bottom. The bottom is put in first and is made about i inch 
thick when the spout has been given the proper pitch. If the 
spout has not been given a proper pitch, the lining is made 
heavier at the end next the cupola and light at the outer end, 
and the pitch given in the lining. This is the common prac- 
tice in short spouts. 

The sides of Ithe ining are built up full at the bottom, so as 
to leave only a narrow groove in the middle and keep the 
stream always in one place, but are sloped back from the 
middle to the top of the spout to give a broad spout surface 
for carrying the stream of iron. A half-round groove i inch 
deep and 2 inches wide at the top is sufficient to carry ofT the 
stream of iron from almost any cupola. But the spout is liable 
to be choked up by dirt from the tap hole or slag, and it is 
made larger for safety. A rammer is seldom used in making 
up a spout and it is generally made up with the hands and one 
of the bod sticks, or the small round stick used to make the 
tap hole. 

When molding sand is used it is worked a little wetter than 
for molding and is beaten down with the bod stick and shaped 
up with the hands and bod stick. When clay or a mixture of 
clay and sand is used, it is worked wet and placed in the spout 
in balls and beaten or pressed into shape with the hands, and 
the bod stick is used to true it up and form the groove in the 
middle. Short spouts are made up with but little difficulty, 
but great care must be taken in making up a long spout to 
have it perfectly true and properly pitched, so that it will clean 
itself of molten iron the moment the cupola is stopped in. 

The greatest strain upon the spout lining is under and 
around the tap hole, where it is liable to be cut away by the 
pressure and current of the stream or to be melted if the 
material is not very refractory, and it may be broken up by 



CUPOLA MANAGEMENT, 89 

the tap bar if not very tenacious when heated to a high tem- 
perature. When molding sand or other materials that do not 
stand a high temperature well, or are not very tenacious when 
heated, are used, a layer of fire clay and sharp sand is placed 
over the lining material under the tap hole. When the heat is 
very heavy and a large amount of iron is drawn from one tap 
hole, a split fire brick is embedded under the tap hole to pre- 
vent cutting and insure a good tap hole throughout the heat. 
The spout is seldom coated or painted with blacking after it is 
made up or dried, but when a friable material is used for lining 
it is sometimes coated with clay wash. 

If the spout is made with a broad, flat bottom the stream 
takes a new course every time the cupola is tapped, and before 
the heat is over the spout is so bunged up that the iron collects 
in pools. A continuous stream cannot, therefore, be main- 
tained the length of the spout, and two or more streams may 
fall from the end of the spout at the same time. To prevent 
this, shape the lining to form a small groove for the stream in 
the center and keep it there every tap. The quality of the 
lining material has a great deal to do with the condition of a 
spout during the running-out of a heat. The spout may be 
cut out in holes by the stream, and pools of iron form in the 
spout at every tap. This is due to the lining material crumb- 
ling and being washed away by the stream. When this does 
not occur every heat with the same material, it is due to the 
material not being properly m.ixed ; but if it does occur every 
heat, it is due to poor material. The spout may become 
choked or bunged up with slag when no slag flows from the 
tap hole with the iron. This is due to the lining melting and 
forming a slag. It is very difficult to keep a spout in order 
through a long heat when this occurs, and the lining material 
should at once be changed. Slag should be removed from the 
spout when very hot by lifting it up with a bar, or chipped 
away with a sharp bar when quite cold. All attempts to re- 
move a tough semi-fluid slag break up and destroy the lining. 



90 THE CUPOLA FURNACE. 

FRONT. 

The front opening of the modern drop-bottom cupola is 
made so small that it is not necessary to place an apron or 
breast plate over it to hold the front or breast in place, as is 
done with the draw-front cupola. The material used for put- 
ting in the front is generally the same as is used in making up 
the spout. The front is generally put in after the fire has 
burned up, but some melters put in the front before lighting, 
and light from the tuyeres. Others make up the tap hole and 
half the front with a stifif mixture of fire clay and sharp sand 
before lighting up, and fill in the other half after the fire has 
burned up. But as a general rule the entire front is left open 
to give draft for lighting, and the front is put in after the fire is 
burned up and about ready for charging. This gives sufficient 
time for drying it before the blast is put on. 

When about to put in the front the ashes and dust are care- 
fully brushed from the spout where the front is to be made, 
and the spout and front opening are wet all around with water 
or clay wash to make the front material adhere and insure a 
good joint. A breast of small pieces of coke is built in front 
of the fire, or a small board cut to fit the front, with a notch in 
the bottom for the tap hole, is placed in front of the fire to 
prevent the front material from being rammed or pressed too 
far back into the cupola. A small iron bar or a round wooden 
stick is then laid in the bottom of the spout to form the tap 
hole. 

If the front is made of molding sand or other material that is 
likely to crumble at the tap hole and be cut away by the stream 
of iron or be broken away by the tap bar, a little fire clay and 
sharp sand, or other refractory material, is placed around the 
bar or stick to form the tap hole. The front material of mold- 
ing sand or loam is then thrown in and rammed solid against 
the board, sides, top and bottom of the opening. If the front 
is made of clay or sand, and worked wet, it is made into balls 
and pressed into place with the hands. When the opening 
has been filled the front is cut away downward and inward from 



CUPOLA MANAGEMENT. 9 1 

ihe top and sides of the opening to the bar forming the tap 
hole, until the latter is not more than i]4 inches long. The 
surplus material from the front is then removed from the spout, 
the bar drawn from tap hole and the front and spout are 
carefully trimmed up. 

If the spout lining and front have been made up with clay 
and sand, or other wet material, a wood fire is built on the 
spout to dry it and the front. When the spout and front are 
made up with molding sand or loam they are generally dried 
by the flame from the tap hole before stopping in, and an iron 
plate is sometimes laid on top of the spout to concentrate the 
heat upon it. 

The front is generally made the full thickness of the lining 
and cannot be forced out by the pressure of molten iron if 
properly put in. When the front material is worked too wet. 
it falls away from the opening at the top when drying, and the 
opening must be closed to prevent the escape of the blast. If 
the tap hole is made too long the iron may chill in it, and the 
cupola cannot be tapped without cutting a new hole. This 
makes very bad work, for the iron is generally melted from the 
old tap hole by the stream passing through the new one, and 
the two holes become one. It is then very difficult to stop in 
or control the flow of iron. 

When the front material is poor it melts into a semi-fluid 
slag that settles down and closes up the tap hole with a tough 
adherent slag that is difificult to remove. When this occurs, 
the tap hole can only be kept open by continually opening it 
up with a tap bar. The only way to overcome this difTiculty is 
to use a more refractory front material. Mineral flu.xes some- 
times make a front material fusible that is not otherwise so. 
When trouble is experienced in keeping the tap hole open 
when using a flux, or after one flux has been substituted for 
another, the composition of the front material must be changed 
or another material used. 

When no board is used and the* front material is rammed 
back into' the fire until it becomes solid in the front, the front 



92 THE CUPOLA FURNACE. 

is ragged and soft on the inside and melts and makes a bad 
tap hole even when the material is good. A good front or 
spout lining can always be made from fire clay and sharp 
sand by mixing them in right proportions for the purpose for 
which they are to be used. 

SIZES OF TAP HOLES. 

The sizes tap holes are made depend upon how the iron is 
to be drawn from the cupola. If it is desired to run a continu- 
ous stream from the cupola, the tap hole is made small to suit 
the melting capacity of the cupola. If it is desired to accumu- 
late a large body of iron in the cupola and fill a large ladle 
rapidly when the cupola is tapped, the hole is made large. 
The tap holes are made of various sizes from ^ inch to i^ 
inches diameter, to suit the different kinds of work. When it 
is desired to run a continuous stream it is very desirable that 
the tap hole should not be cut and enlarged by the stream. 
This is generally prevented by placing a very refractory 
material around the rod forming the tap hole. But some 
nielters have a form in which they mould a tap hole from a 
carefully prepared material that will not cut, and dry it in an 
oven or on a stove. This tap hole form, when thoroughly 
dried, is placed in position on a split fire-brick and the front 
made up around it, which always insures a regular sized hole 
throughout the heat. 

LOCAIING THE TAP HOLES. 

We have already described the manner of putting in the front 
and forming the tap hole, and shall here only consider the loca- 
tion and number of tap holes. The tap hole is placed in the 
side of the cupola from which it is most convenient to convey 
the iron to the work to be poured, and it makes no difference in 
the working of the cupola upon which side it is placed if the 
bottom is sloped to throw the iron to the hole. One tap hole 
is sufificient to run the iron from any ordinary cupola, but two are 
frequently put in. In some cupolas two fronts and tap holes 



CUPOLA MANAGEMENT. 93 

are put in side by side only a few inches apart, and two spouts 
are made up so that the tap hole can be kept in better order 
for drawing ofif the iron. They are tapped turn about, and in 
case too great a quantity of melted iron accumulates in the 
cupola they are both opened at one time. Two tap holes 
placed in this way can only be worked for hand ladle work at 
the same time, and they cannot be worked to advantage even 
for that, for they are so close together the men are in each 
other's way. One tap hole if properly made and managed will 
run off all the iron a cupola will melt, and it is poor cupola 
practice to put in two fronts and tap holes in this way. 

Two tap holes are frequently placed in a cupola for con- 
venience in carrying the iron from the cupola to the molding 
floors. They are generally placed on opposite sides of the 
cupola, to save carrying the iron around the cupola or from 
one molding room to another. Two tap holes are also placed 
in cupolas to facilitate the removal of the iron in hand ladles. 
Six 40-pound hand ladles are all that can be safely taken from 
a spout per minute. When more than this number of ladles 
are filled and removed per minute, the men have to move so 
rapidly there is danger of a clashing of ladles and spilling of 
iron, and when a heavy stream once gets away from the men 
and falls to the floor, it spatters and flies so that it is difficult 
to stop in or again catch it. When more than 8 tons are 
melted per hour in a cupola for hand ladle work, two tap holes 
are always put in. They are placed in the side of the cupola 
that is nearest the work to be poured, but always at a sufificient 
distance apart to admit of the men catching at one spout being 
out of the way of those catching at the other. 

SLAG HOLE. 

A slag hole for drawing ofif slag is sometimes placed in a 
cupola, but it is not used except when the cupola is run be- 
yond the capacity to which it can be run successfully without 
slagging. The hole is placed below the level of the tuyeres, 
and when it is desired to accumulate a large body of molten 



94 THE CUPOLA FURNACE. 

iron in a cupola the slag hole is placed high. When the iron 
is drawn from a cupola as fast as melted the hole is placed low 
The opening through the casing and lining is generally made 
oval and about 3x4x5 inches. 

The slag hole front when the hole is placed high consists of a 
plug of the same material used for the tap hole front. The 
plug is placed in the outer end of the opening and is from 2 to 
3 inches thick. A hole i inch diameter is made through it for 
a tap hole* and the plug or front is cut away from the edges of 
the casing to the hole until the latter is not more than lyi 
inches long. When the hole is placed low and the slag per- 
mitted to flow throughout the heat after it is opened, the plug is 
made of loam or molding sand mixed with a little blacking to 
make it porous when heated, and the plug is placed in the hole 
on the inside, flush with the lining. No tap hole is made 
through the plug when placed in this way, and when it is 
desired to tap slag a hole is cut through it with a sharp-pointed 
tap bar. This material does not bake hard, and the entire plug 
may be cut out when necessary. 

Slag chills more rapidly in a tap hole than iron, and is more 
difificult to tap or draw from a cupola, and when the slag hole 
is not properly arranged it cannot be drawn at all. If the tap 
hole is made small and long the slag chills in the hole and it is 
difificult to open the hole or keep it open. When the lining is 
very thick it must be cut away and the hole made large inside 
of the front, or the slag will chill in the lining the same as it 
might in the hole in the front. The hole in the lining can be 
made 6 or 8 inches diameter without injuring the lining, and a 
hole of this size will admit a sufificient quantity of slag to the 
tap hole to prevent it chilling. There is never any difficulty 
from the slag chilling when the front and tap hole are placed 
flush with the inside of the lining, for the slag is kept hot and 
fluid in the cupola, and may be drawn ofT whenever there is a 
sufificient quantity in the cupola to flow from it. It is therefore 
better to cut away the casing and lining, and place the front 
flush with the inside of the lining. 



CUPOLA MANAGEMENT. 95 

LIGHTING UP. 

When the cupola is small the shavings are thrown in from 
the charging door and evenly distributed over the bottom. 
The wood is cut short and split fine and dropped down, a few 
pieces at a time, and so placed that the fire will burn up evenly 
and quickly. When the cupola is large the melter goes down 
into it and his helper passes him down the shaving and wood 
from the charging door. The shavings are evenly spread over 
the bottom, care being taken to get plenty around the outside 
to insure a good light. A layer of fine, light dry wood is then 
laid over the shavings, and on this a layer of heavier wood, 
and so on until the required quantity of wood for lighting the 
bed is placed in the cupola. Care is taken to arrange the 
wood so that it will burn up evenly and quickly. A light dry 
wood should be used, and the pieces must not be very large, or 
too much time will be consumed in burning them, and the bed 
will settle unevenly. 

When the wood has been arranged the melter gets out and a 
thin layer of small coal or coke is placed over the wood. The 
bed fuel is then thrown in evenly over the wood. All the bed 
is put in but a few shovelfuls, which are kept to fill up any 
holes that may be formed by an uneven settling. The charg- 
ing door is then closed and the shavings lighted at the front 
opening. The tuyere doors are opened to give draft and the 
fire left to burn up. When the wood is nearly burned out and 
there is a good fire of hot coals at the front and tuyeres, the 
melter generally puts in the front and spout and builds a wood 
fire on the spout to dry them. He then looks in at the charging 
door, and if the smoke is burned ofT and the fire beginning to 
show through the top of the bed, he puts in the remaining few 
shovelfuls of fuel and makes the top of the bed as level as pos- 
sible. He then closes all the tuyere doors but one and begins 
charging the iron into the cupola. 

Straw may be used in place of shavings for lighting up when 
shavings cannot be procured. The wood should be dry pine 
or other light wood, and it must not be used in too large sticks 



96 



THE CUPOLA FURNACE. 



or the bed will be burned too much before the wood is burned 
out; and if the iron is charged before the wood is burned out, 
the latter smokes and the melter cannot see how to place the 
iron or fuel. For the same reason, hard or green wood should 
not be used in lighting up. 

When the bed burns up on one side and not on the other in 
a small cupola, the bed may be burned up on the other side 
after the blast is put on and the heat run ofT successfully. But 

Fig. 25. 




when the bed burns up on one side and not on the other in a 
large cupola the bottom had better be dropped at once. We 
once had to drop the bottom of a 60-inch cupola before the 
heat was half ofif, for the reason that the melter was careless in 
arranging the wood and lighting up, and charged the iron with 
the bed only burned up on one side. He thought the blast 
would make it burn up on the other side, but it did not, and 



CUPOLA MANAGEMENT. 



97 



the heat was a failure. Never burn the bed up to warm or 
heat up the cupola, for a cupola does not require to be heated 
before it is charged, and the lining burns out fast enough with- 
out wasting fuel to burn it out. 

NEW METHOD OF LIGHTING UP. 

A new method of lighting up or starting the fire in a bed 
has recently been introduced by means of the Buckeye Heater 
or oil torch, as shown in Fig. 25. By the employment of a 

Fig. 26. 




torch of this kind the use of shavings wood or other kindling 
material, may be entirely dispensed with, and the coke of the 
bed ignited by the flame of the torch alone. In very small 
cupolas, the bed may be ignited from the front without diffi- 
culty, but in large cupolas, it is necessary to make openings or 
flues through the coke upon the sand bottom, as shown in 
Fig. 26, through which the torch fiame may penetrate to 
ignite the bed evenly. These flues may be made by building 
7 



98 THE CUPOLA FURNACE. 

up pieces of coke to form them or by constructing them of 
thin board. 

The latter is said by founders, using the torch to be the 
better way, as the flues can be formed with less labor and more 
certainty, and the thin boards rapidly burn away, and serve as 
fuel in igniting the coke. These torches are used in the 
foundry, for skin drying, lighting, and heating, and there are 
various kinds of them on the market, any of which may be 
used for lighting up the copola. But those used in connection 
with a compressed air plant are the best for this purpose, as 
the flame is stronger, and may be forced further into the 
cupola. The hand torch requires more time for lighting up, 
and a little wood is also sometimes necessary. 

THE BED. 

Iron is melted in a cupola within a limited space, known as 
the melting-point or meliing zone. The melting point is the 
highest point in a cupola at which iron is melted properly, and 
the melting zone is the space between the highest and lowest 
points at which iron melts properly. Iron may be melted to a 
limited extent above or below these two points, but it is burned, 
hardened and generally dull. The melting zone extends across 
the cupola above the tuyeres, and is from 6 to 8 inches in 
depth. Its exact location is determined by the volume of blast 
and the nature of the fuel employed in melting. A large 
volume of blast gives a high melting-point, and a small volume 
a low melting-point. A soft, combustible fuel gives a high 
melting-point, and a hard fuel a low melting-point, the blast 
being equal in volume with both fuels. 

To do good melting the melting-point must be discovered, 
and only a sufficient quantity of fuel placed in the bed to bring 
the top of the latter up to the melting point. When the fuel 
is hard anthracite coal, the rule is to use a sufficient quantity 
of coal in the bed to bring the top of it 14 inches above the 
top of the tuyeres when the wood is burned out ; with hard 
Connellsville coke 18 inches, and with soft coke 20 to 25 inches. 



CUPOLA MANAGEMENT. 99 

But the melting point is varied by the volume of blast and 
these rules do not always hold good. So the melting point in 
each cupola must be learned to get the best results from the 
cupola. 

To find the melting point a bed is put in according to the 
rule and iron charged upon it. If the iron is a long time in 
coming down after the blast is put on, or the iron melts very 
slowly during the melting of the first charge, but melts faster 
at the latter end of the charge and is hot, the bed is too high 
and the iron is being melted upon the upper edge of the melt- 
ing zone. Fuel and time are then being wasted, and the fuel 
should be reduced so as to place the iron at the melting point 
when melting begins. If the iron comes down quick but is 
dull, or if it comes slow and dull, and does not grow hotter at 
the latter end of the charge, the melting is being done on the 
lower edge of the melting zone, and the quantity of fuel should 
be increased to bring the top of the bed up to the melting 
point. When the top of the bed is placed only halfway up 
the melting zone, the iron comes down hot and fast, but the 
bed does not melt the quantity of iron it should and the latter 
part of the charge on the bed is dull. The latter part of the 
charge on the bed when the bed is the proper height is also 
dull if the charge is too heavy for the bed, and care must be 
taken in noting this point. 

If by comparison with the charges of iron in various sized 
cupolas the charge on the bed is found to be light, the bed 
should be raised until the melting indicates that it is at a 
proper height; then the weight of iron on the bed may be in- 
creased, if the charge is too light. When raising or lowering a 
bed, it should be done gradually by increasing or decreasing 
the fuel from 50 to 100 pounds each heat until the exact 
amount of fuel required in the bed is found. If the changes in 
the bed are made gradually in this way, the efifect of the 
changes upon the melting may be observed more accurately, 
and better results obtained than when a radical change is made 
by increasing or decreasing the fuel in large amounts at one 



lOO THE CUPOLA FURNACE. 

heat. When the amount of fuel is found that brings the top of 
the bed to a height that gives the best results in melting, the 
top of the bed is maintained at that point each heat. 

When a cupola is newly lined the diameter is decreased from 
what it was with the old lining, and the weight of fuel in the 
bed must be decreased to bring the top of the bed down to the 
melting point, and as the lining burns out and the cupola gets 
larger the fuel must be increased to keep the bed up to the 
melting point. Trouble is often experienced in melting after a 
cupola has been newly lined. This is because the diameter of 
the cupola is reduced from 6 to lo inches, and the bed and 
charges are not changed to correspond with the reduced size 
of the cupola. There is never any trouble of this kind in 
foundries where a cupola book is provided and a record kept 
of the melting from one year's end to another, for the melter 
or foreman can then look back and see the weight of the bed 
and charges when the cupola was newly lined, and the increase 
made in the weight as the lining burned out and the diameter 
increased. 

No definite or even approximate weight can be given of the 
amount of fuel required for a bed in cupolas of different 
diameters, for the tuyeres are placed at such a variety of 
heights above the sand bottom that for two cupolas of exactly 
the same diameter twice the quantity of fuel may be required 
for a bed in one as is required for a bed in the other. Cupolas 
with two or three rows of tuyeres require a larger amount of 
fuel for a bed than cupolas with but one row, but the same 
general directions for burning and managing the bed apply to 
all cupolas. 

CHARGING. 

The old way, and the way still in vogue in some localities, of 
stocking, loading or putting the fuel and iron into a cupola is 
to place a sufficient quantity of fuel in the cupola to fill it above 
the tuyeres. On this fuel or bed are placed from 50 to 500 
pounds of iron, according to the size of the cupola, then from 
one to four shovelfuls of fuel are put in and from 50 to 200 



CUPOLA MANAGEMENT. lOI 

pounds of iron, and so on until all the iron to be melted is 
placed in the cupola. 

This way of stocking a cupola mixes the fuel and iron in the 
cupola and they come down to the melting point together. 
The fuel fills a space that should be filled with iron, and a great 
deal of the melting surface of the cupola is lost, and its melting 
capacity reduced in proportion. 

The modern way of stocking a cupola is to put in the fuel 
and iron in layers or charges. Each layer or charge of fuel is 
separated from the layer or charge above and below it by a 
layer or charge of iron, and each layer of iron is separated by 
a layer of fuel. This way of stocking a cupola is known as 
charging the cupola. When a cupola is charged in this way 
the iron comes down to the melting point in a body extending 
over the melting surface of the cupola, and the entire melting 
surface is utilized. The melting capacity of a cupola is about 
one-half greater when charged in this way than when the fuel 
and iron are mixed, and the consumption of fuel is also less. 

The first charge of iron is placed on the bed at the melting 
point. In melting this charge of iron a certain amount of fuel 
is consumed and the top of the bed settles down from the top 
of the melting zone to the bottom of the melting zone. The 
charge of fuel on top of the charge of iron that has just been 
melted settles with the iron until it unites with the bed, and 
places the top of the bed again at the top of the melting zone, 
ready to melt the ne.xt charge of iron, and so on with each 
succeeding charge of fuel and iron throughout the heat. This 
is the correct theory of melting iron in a cupola, and the prac- 
tice that must be followed to obtain the best results from a 
cupola. 

Now, having described the theory of charging and melting, 
let us consider the practical working of a cupola upon this 
theory. The amount of iron placed upon the bed in the fir.-t 
charge and in each charge through the heat must be the exact 
amount of iron the fuel will melt while settling from the melt- 
ing point to the bottom of the melting zone. The amount of 



I02 THE CUPOLA FURNACE. 

fuel in each charge must be the exact amount required to raise 
the bed from the bottom of the melting zone to the melting 
point. If the charges of iron are made too heavy the iron 
comes dull at the latter end of the charge and hot at the first of 
the charge until a few charges have been melted, when it comes 
dull all through to the end of the heat. When the charges of 
iron are too light the iron comes hot, but there is a stoppage 
in melting at the end of each charge, changing to continuous 
but very slow melting as the heat progresses. 

When the charges of fuel are too heavy the iron melts slowly 
and unevenly, and if the heat is a long one it comes dull and is 
hardened in melting. When the charges of fuel are too light 
and the charges of iron heavy, the result is dull iron. When 
the charges of fuel and iron are both too light the iron gener- 
ally comes hot but slowly throughout the heat, and the full 
melting capacity of the cupola cannot be realized. 

There is no rule for making the weight of the first charge of 
iron of any definite proportion to the weight of the bed of 
either anthracite coal or coke that holds good in all cupolas. 
Manufacturers of some of the patent cupolas have such a rule 
for their cupolas that is approximately correct, but the tuyeres 
in different sizes of these cupolas are always placed at the 
same height and about the same amount of fuel is required for 
a bed. The bed will melt a heavier charge of iron in settling 
than the other charges of fuel, and the first charge is generally 
made from one-third to one-half heavier than the subsequent 
charges. The weight of the first charge of iron varies from 
two and one-half to four and one- half times the weight of the 
bed with anthracite coal ; with coke the weight of the first 
charge varies from one and one-half to three and one-half times 
the weight of the bed. 

These wide variations in the weight of the first charge of 
iron in proportion to the weight of the bed are largely due to 
the difference in the height of tuyeres and the large amount of 
fuel required for a bed in a cupola with very high tuyeres. 
But variation is also due in many cases to bad judgment in 



CUPOLA MANAGEMENT. IO3 

estimating the weight the first charge should be. The greater 
the weight of the first charge in proportion to the weight of 
the bed, the better the average will be in melting, and careful 
experiments should be made with every cupola to learn the 
largest amount of iron it will melt on the bed with safety, and 
that amount should always be placed in the first charge. 

There is no rule for making the weight of the charges of fuel 
or iron of any definite proportion to the weight of the bed or 
first charge of iron, and the weight of the charges of both fuel 
and iron is frequently changed in different parts of the heat, 
to give a hotter iron for some special work, or to make the iron 
run of an even temperature throughout the heat. In practice, 
the weight of the charges of iron to the charges of anthracite coal 
varies from 6 to [4 pounds of iron to the pound of coal. With 
coke they vary from 6 to 15 pounds of iron to the pound of 
coke. These variations in the per cent, of iron to fuel are due 
in many cases to the quality of fuel and in many other cases, 
to poor judgment in working the cupola. In all cases the 
charge of iron should be made as heavy as the charge of fuel 
will melt and produce good hot iron for the work, for this is 
the only way a good per cent, of iron to the pound of fuel can 
be obtained. 

PLACING THE CHARGES. 

The top of the bed is made as level as it can be before 
charging the iron, and the smoke must all have disappeared 
so the melter can see how to place the charges. When the 
cupola is very high a few hundred of stove plate or other light 
scrap is placed upon the bed to prevent the heavy pieces of 
pig or other iron breaking up the fuel and settling down into 
the bed when thrown in. The pig should be broken into short 
pieces and placed in the cupola with the end toward the lining. 
The pieces of pig or other iron are placed close together so as 
to utilize all the heat and prevent its escape up the stack, and 
each charge is made as level as it can be on top. The gates 
and cupola scrap are placed on top of the pig and are used to 



I04 THE CUPOLA FURNACE, 

fill up holes and level up the charge. Old scrap is generally 
charged with the pig when heavy, and on -top of the gates, 
when light. Rattle barrel iron and gangway scrap or riddlings 
go in with the gates, a few shovelfuls to each charge. 

The charge of fuel is distributed evenly over the charge of 
iron, and the second charge of iron is put in the same as the 
first, and the second charge of fuel the same as the first, and 
so on until the cupola is filled to the charging door. Charging 
is then stopped and the door closed until the blast goes on. 
When melting begins the stock begins to settle, and the door 
is opened and charging continued as before until all the iron to 
be melted is placed in the cupola. While charging is going 
on the cupola is kept filled to the charging door to prevent the 
gas igniting and making a hot flame at the charging door, 
which makes it hot for the men and difificult to place the 
charges of fuel and iron properl3\ When charging is finished 
the charging door is closed to prevent sparks or pieces of 
burning fuel being thrown upon the scaffold. 

When the charges have been arranged, the next important 
matter to be considered is the placing of iron in the cupola. 
To obtain an even quality of iron at the spout, too great care 
cannot be taken in charging, for this is the first step in mixing 
irons when melted in a cupola. This is an important matter 
that does not appear to be fully understood by melters, and 
irons are frequently placed in cupolas without any regard to 
mixing them, under the impression that irons mix when 
melted ; which is not the case, if irons are not placed so that 
they come in direct contact with each other in small bodies, as 
soon as melted. 

When not mixed in charging, and the iron drawn close in 
small ladles, the different grades of iron charged may be drawn 
from the cupola and found in the casting without having mixed 
with each other, and this is frequently the cause of hard and 
uneven castings. 

No rule can be given for mixing irons in charging that will 
hold good in all cases, owing to the great differences in iron 
melted for the various classes of work. 



CUPOLA MANAGEMENT. IO5 

In some foundries pig is melted with only a limited amount 
of remelt scrap;* in others the remelt is more than fifty per 
cent, of the entire heat; while in others the greater part of the 
heat is old scrap. 

When melting pig with a limited amount of remelt scrap 
only, the pig should be placed on the bed and charges of fuel, 
as should also pieces of scrap that are as heavy as pig, and on 
this a limited amount of light scrap should be placed. Each 
charge of pig should be made as level as possible on top, and 
the light scrap evenly distributed over it. When charged in 
this way the scrap melts at the same time as the pig, and a 
thorough mixture of the pig and scrap is effected at the spout. 

When charging pig of dififerent grades no two pieces of the 
same grade should be placed togeiher if it can be avoided. 
This gives a better mixture than when all of one grade is 
placed on one side of a cupola and another grade on the other 
side. 

The pig should be placed with one end toward the lining as 
far as possible, and the side of a pig should never be placed 
against the lining, for a pig so placed is protected to a greater 
or less extent from the heat by the lining, and does not melt so 
freely as when fully exposed to the heat, and is frequently 
found lodged over the tuyeres in cinder, adhering to the lining. 

When melting pig with a large per cent, of remelt, such as 
small gates and light scrap, the pig should be broken into four 
or more pieces, for pig melts from the freshly broken ends, and 
when broken short melts more readily, and may be melted 
almost as quickly as gates and other foundry scrap that is pro- 
tected to a greater or less extent against melting by a coating 
of sand. 

The charges when heavy should be divided into from two to 
four parts or drafts, and a layer of pig placed upon the fuel, 
upon this a layer of scrap, upon this a layer of pig, and so on 
until the entire charge is put in. 

When pig and a large per cent, of scrap are mixed in this 
way in charging, a better mixture is obtained at the spout than 



'lO'j THE CUPOLA FURNACE. 

when all the pig is placed upon the fuel and the scrap on top 
of it. 

When melting old scrap and pig the manner of charging 
must depend to a large extent upon the character of the scrap. 
When the scrap is heavier than the pig it should be placed 
upon the bed and fuel in the charges, and the pig on top of it. 
If the scrap is as heavy as the pig, it should be mixed with the 
pig. When light and in small quantities, it should be charged 
on top of the pig; and when fifty per cent, or more of the heat 
is light scrap, it should be mixed with the pig in the same 
manner as when melting a large per cent, of gates and foundr}- 
scrap. 

A poor heat was never melted because the melter failed to 
put up the bottom doors, put in a sand bottom, light a fire, or 
to charge fuel and iron. It is not the failure of the melter to 
do these things that causes poor melting, but his failure to look 
after the small details in doing them. 

When the iron that has been charged is all or nearly all 
melted, and it is discovered there is not suf^cient iron in the 
cupola to pour ofT the work, more iron is sometimes charged. 
At this stage of the heat the stock is so low in the cupola and 
the heat ii so intense that the cupola is in a very bad condi- 
tion for resuming charging to melt more iron. It is only a 
waste of fuel to charge it into the cupola at this stage of the 
heat, and the only iron that can be melted on the fuel already 
in the cupola is light scrap, and but a limited quantity of it. 
When the charging door is opened the heat at the opening is 
so intense that the men cannot go near it, and the scrap must 
be thrown in from a distance or by standing alongside of the 
cupola out of the heat and throwing the iron around into the 
door on a shovel. 

Poor melting may be due to bad charging. Iron or fuel 
should never be dumped into a cupola from a barrow, for it all 
falls on one side of the cupola. The iron generally lies where 
it falls in a pile, and the fuel rolls on the other side of the 
cupola, and good melting cannot be done with the fuel on one 



CUPOLA MANAGEMENT. lO/ 

side and the iron on the other. This way of charging is about 
equal to the old way of mixing the fuel and iron, and only 
about one-half of the melting capacity of the cupola can be 
realized. Fuel should never be emptied into a cupola from a 
basket or box, for it all falls in one place and cannot be spread 
evenly over the charge of iron. To charge a cupola properly 
the iron must all be thrown in with the hands, and the fuel 
with a shovel or fork. 

CHARGING FLUX, 

When it is desired to tap slag, the slag-producing material or 
flux is charged in the cupola on top of the iron and evenly dis- 
tributed. The flux is sometimes put on each charge of iron, 
but generally about one-sixth of the heat is charged without 
flux. After that, flux is put in on every charge of iron except 
the last one or two charges, where it is not required if the 
proper amount has been used through the heat. The quantity 
of flux required depends upon the slag-producing propensity of 
the material used and the condition of the iron charged, and is 
from 30 to 100 pounds to the ton of iron melted. If the iron 
to be melted is all clean iron, the amount of flux required is less 
than when the iron is dirty scrap or a large per cent, of the heat 
is sprues and gates that have not been milled and are melted 
with a heavy coating of sand on them. 

If it is not desired to tap slag and the flux is used only to 
make a brittle slag in the cupola, it is charged in small quanti- 
ties of from 5 to 10 pounds to the ton of iron, and is placed 
around the outside of the charge near the lining. Flux is 
sometimes charged in a cupola in a sufficient quantity to pro- 
duce a large body of slag through which to filter the molten 
iron and cleanse it of impurities, but not in a sufficient quantity 
to admit of slag being drawn from the cupola. This way of 
fluxing works very well in a short heat, but in a long heat the 
slag sometimes absorbs a large amount of impurities, becomes 
overheated and boils up in the cupola and fills the tuyeres, 
and when boiling it cannot be drawn from the cupola at the 
slag hole and the bottom generally has to be dropped. 



I08 THE CUPOLA FURNACE. 

BLAST. 

Before the blast is put on the tuyere doors are all tightly 
closed and luted to prevent the escape of any of the blast dur- 
ing the heat, and they should be examined from time to time 
to see that the luting has not blown out and the blast is not 
escaping. The blower is speeded up to the full speed at once, 
and the full volume of blast given the cupola from the start. 
The old way of putting on the blast light and increasing or 
decreasing it at dififerent stages of the heat has been aban- 
doned by practical foundrymen, and the cupola is given the 
same blast from the beginning to the end of the heat. This is 
the only way good melting can be done in a cupola charged in 
the manner before described. If the cupola does not work 
properly, remedy the evil by changing the charges, but never 
vary the blast in dififerent parts of a heat to improve the 
melting. 

When the blast is first put on, it is indicated by a rush of 
it from the tap hole and at the charging door by a volume 
of dust passing up the stack. Then follows a bluish-colored 
gas which bursts into a bluish flame as the stock settles, chang- 
ing to a yellowish hot flame as the stock sinks still lower. If 
the stock is kept up level with the charging door in a cupola 
of good height the gas does not ignite, and it is the aim of the 
chargers to keep the stock up to this point until they are 
through charging. When the blast is shut ofT from a cupola 
for any cause or at the end of the heat before the bottom is 
dropped, one or more of the tuyere doors are at once opened 
to prevent gas from the cupola passing into the blast pipe, 
where it is liable to explode and destroy the pipe. 

The full consideration of the blast for a cupola would take up 
more space than we care here to give 'to it and would lead our 
readers too far from the subject of working a cupola. We shall 
therefore leave it for fuller consideration under another heading. 

MELTING. 

Melting begins in a cupola soon after the blast is put on, 



CUPOLA MANAGEMNNT. IO9 

and the exact length of time is indicated by the appearance of 
molten iron at the tap hole. When the iron is charged two or 
three hours before the blast goes on, and the bed is not too 
high, iron flows from the tap hole in from three to six minutes 
after the blast is on. When the iron is charged and the blast 
is put immediately on, iron appears at the tap hole in from 15 
to 20 minutes after the cupola is filled if the bed is not too 
high. When the bed is too high, iron melts only when the sur- 
plus fuel is burned up and permits it to come down to the melting 
point, and it is very uncertain when melting will begin; and it 
is generally from half an hour to an hour before any molten 
iron appears at the tap hole. If iron does appear at the tap 
hole within 15 or 20 minutes after the blast is on, the bed is 
either too high or the fire has not been properly lit, and the 
bed is not doing its work efficiently. 

Foundrymen differ as to the time for charging the iron before 
the blast is put on. Some claim that fuel is wasted by lighting 
the fif-e early and charging the iron two or three hours before 
the blast is put on, while others claim fuel and power are only 
wasted by putting on the blast as soon as the iron is charged. 
We have melted iron in both ways, and we prefer to charge the 
iron from two to three hours before the blast is on, except 
when the cupola has a very strong draft that cannot be shut 
off, as is sometimes the case when there is no slide in the blast 
pipe for shutting off the blast, and as air is supplied to the 
cupola through the pipe. When iron is charged and the 
cupola filled to the charging door with fuel and iron, and the 
draft shut off" from the cupola, the combustion of fuel in the 
bed is very light and the heat that rises from it is utilized in 
heating the first charge of iron. When the blast is put on, this 
charge of iron is ready to melt and iron comes down in a 
few minutes. When the blast is put on immediately after the 
cupola is charged the iron is cold, and time is required to heat 
it before it will melt, and the blower must be run 15 or 20 
minutes before iron appears at the tap hole, and the first charge 
melts more slowly than when the iron has been heated before 
the blast is put on. 



IIO THE CUPOLA FURNACE. 

We think the best way is to put on the blast about two hours 
after the charging begins. When the blast goes on, the tap 
hole is open and is left open until the iron melts and runs hot 
and fiuid from it. From lO to 20 pounds are generally per- 
mitted to run from the spout to the floor to warm the spout 
and insure the iron being sufificiently hot not to chill in the tap 
hole after stopping in. The first iron melted is always chilled 
and hardened to some extent by the dampness of the sand bot- 
tom and spout, and when the work is light and poured with 
hand ladles, a small tap of a few ladles is made in a few minutes 
after stopping in, and the iron used for warming the ladles and 
it is then poured into the pig bed or some chunks In some 
foundries the cupola is not stopped in at all after the iron 
comes down. The first iron is used to warm the ladles, and as 
soon as the iron is hot enough for the work the molders begin 
pouring it. We recently ran ofT a heat of 3 i tons in this way 
from a cupola for hand-ladle work without using a single bod 
for stopping in. Another practice is to close the tap hole be- 
fore putting on the blast. This is done by packing the tap 
hole full of dry parting sand to prevent the first iron melted 
from entering the hole and becoming chilled in it. The sand 
is pushed well back into the hole with a small rod, and a thin 
layer of clay is rubbed over the opening to prevent the sand 
from being blown out. This thin layer of clay is readily broken 
away and an opening made through the dry sand with a small 
rod. The iron flowing through this opening washes out the 
sand in a very short time and leaves a clean tap hole. When 
the latter is closed in this way, the first tap is made in the 
number of minutes after the blast is put on that practice has 
shown to give a desired amount of iron for the tap, or the 
tuyeres are watched for the rise of molten iron in the cupola 
for the tap. The practice of permitting the tap hole to remain 
open until the iron begins to come down fast and hot has the 
advantage of thoroughly drying the bottom front and spout 
before the work of pouring begins. Closing the tap hole saves 
the remelting of the iron flowing from it on the floor, and also 



CUPOLA MANAGEMENT. I I I 

loss by escape of blast. But it requires more care in drying 
the front and spout and also renders the first tap somewhat 
harder than subsequent taps, so that it is only a matter of 
choice of which practice should be followed. 

When the iron is handled in large ladles a tap is not made 
until a sufificient quantity is melted to fill a ladle, or there is a 
suflficient body of iron in the cupola to insure it not chilling in 
the bottom of a large ladle before another tap is made. When 
the blast blows out at the tap hole after a tap is made, it indi- 
cates that the melted iron is all out of the cupola, or the tap 
hole is too large, and the cupola should be stopped in until iron 
collects in the bottom, or the size of the tap hole should be re- 
duced to prevent the escape of the blast. The size of the tap 
hole is reduced when it becomes too large to run a continuous 
stream without blowing out, by stopping in with a bod of stiff 
clay and sand that will not cut, and as soon as the bod is set, 
cutting a new tap hole through the bod with the tap bar. Iron 
should be melted hot and fast, and it should never be drawn 
from a cupola for any kind of foundry work if it is not hot and 
fluid enough to run stove plate or other light castings. Iron is 
not burned in a cupola by melting it hot and fast, but is burned 
and hardened by melting it too high in the cupola and melting 
it slow and dull. 

Nothing is gained by holding molten iron in a cupola to keep 
it hot, for it can be kept as hot in a ladle as in a cupola, and 
iron should be drawn from a cupola as fast as melted or as fast 
as it can be handled in pouring the work. If we were running 
a foundry we should never stop in the cupola except to get 
enough iron to give a gang of men a hand-ladle full all around, 
or to remove a large ladle from the spout. When the cupola 
is very small and melts slowly it is sometimes necessary to stop 
in and collect iron in the cupola, but it is not necessary to stop 
in a large cupola for this purpose. If the iron is all poured 
with hand-ladles the men should be divided into gangs, with 
only enough men in each gang to take away the iron as fast as 
melted. If this is not done and there is a large number of men. 



112 THE CUPOLA FURNACE.' 

the ladles get so cold between catches that they chill the iron 
before it can be poured, and the melter is blamed for not mak- 
ing hot iron. 

The flow of iron from the tap hole indicates how the cupola 
is melting. If it has been properly charged the flow will be 
even in quantity and temperature throughout the heat, except 
in a very long heat, when the stream will get smaller and 
the cupola not melt so fast toward the end of the heat. When 
too much fuel is used the iron melts slowly and grows dull as 
the heat progresses. When the charges of iron are too heavy 
the iron is not of an even temperature throughout the heat, but 
is dull at the latter end of every charge and hot at the beginning 
of the next charge. When the charges of fuel are too heavy the 
iron melts very slowly at the beginning of each charge and fast 
at the latter end, and if the charges of iron are also too heavy, 
the iron i^ dull at the latter end of the charge. If the cupola 
melts unevenly it is not being properly worked, and the mode 
of charging should be changed until it does melt evenly from 
the beginning to the end of the heat. 

POKING THE TUYERES, 

When the blast is first put on, the fuel in front of each tuyere 
is bright and hot, but it is soon chilled and blackened by the 
large volume of cold blast passing in, and the tuyere presents 
the appearance of being closed up and admitting no air to the 
cupola. The blast when first put on does not remove the fuel 
and make a large opening in front of each tuyere to get into 
the cupola, but works its way between the pieces of fuel in 
front of the tuyeres, and these openings remain open for the 
passage of blast after the fuel becomes cold and black. The 
blast, therefore, passes into the cupola just the same as when 
the fuel was hot, and it is not necessary to poke the tuyere 
with a bar or break away the cold fuel in front of each tuyere 
to let the blast into the cupola. 

Toward the end of a long heat, slag and cinder settle and 
chill at the bottom of a cupola, and often not only close ofif 



CUPOLA MAXAGEMENT. II3 

the blast at the tuyeres, but prevent it passing freely through 
the stock and out at the top. If the tuyeres are poked at this 
stage of the heat an opening may be made well into the stock. 
But in working the bar around in formmg this opening most of 
the natural passages the blast has made for entering the stock 
are closed up. The new opening is only a hole bored into a 
tough slag or cinder from which there is no way for the blast 
to escape into the stock, and less blast enters a cupola after the 
tuyeres have been poked and opened up than entered before. 
The only time a tuyere should be poked with a bar is when 
cinder or slag has lodged or formed in front of it in such a way 
as to run a stream of molten iron into the tuyere. The tuyere 
door should then be opened and the slag or cinder broken 
away with a bar to prevent the iron running into the tuyere. 

FUEL. 

Theoretically ten pounds of iron are melted with one pound 
of anthracite coal, and 15 pounds with a pound of Connells- 
ville coke. But this melting is done in the foundry office or in 
the mind of the foreman, and it takes a little more fuel to melt 
iron in a cupola for foundry work. Six pounds of iron to i of 
anthracite coal and 8 pounds of iron to i of Connellsville coke 
is by practical foundrymen considered good melting. A little 
better than this can be done in a full heat for the size of the 
cupola and under favorable circumstances, but in the majority 
of foundries fewer pounds of iron are melted to one of fuel than 
the above amount. 

It is sometimes necessary for the melter to put in a few extra 
shovelfuls of fuel when the bed has been burned too much be- 
fore charging, or to level up the charges when two or three 
men are shoveling in fuel at the same time and get it uneven. 
The melter is generally blamed if the iron from any cause comes 
dull, and he will generally put in a few extra shovelfuls of fuel 
the next heat to make it hot, and if the iron does come hot the 
next heat the extra shovelfuls are put in every heat, but are not 
put on the cupola report. In this way foundrymen are often 



114 THE CUPOLA FURNACE. 

misled by the cupola report and suppose they are melting 
more pounds of iron to the pound of fuel than they really arc. 
The only way the foundryman can know exactly how man}' 
pounds of iron he is melting to the pound of fuel is to have an 
accurate account kept of the amount of iron melted and com- 
pare it with the amount of fuel bought and delivered for the 
cupola, after deducting from it any amount that may have been 
consumed in stoves and core ovens. 

We recently met a foundryman who thought he was melting 
14 pounds of iron to the pound of fuel, but when he came to 
compare the iron melted with the fuel bought and delivered for 
the cupola he found he was only melting about 7 pounds of 
iron to the pound of fuel ; and about the same results would be 
found in every foundry that is claimed to be melting a very 
large per cent, of iron to fuel. There is nothing gained by 
saving a few cents' worth of fuel in the cupola and losing a 
dollar's worth of work on the floor by dull iron, and there is 
nothing gained by using too great a quantity of fuel, for too 
much fuel in a cupola makes dull iron, as well as too little fuel. 

Iron is not melted in a cupola for the fun of melting it or to 
learn how many pounds of iron can be melted with a pound of 
fuel, but is melted to make castings. What the foundryman 
wants from the cupola at the tap hole is an iron hot and fluid 
enough to make a sound casting, regardless of the amount of 
fuel required to produce it. As before stated, iron cannot be 
melted hot and fast in a cupola with either too much or too 
little fuel, and foundrymen have only to melt their iron as hot 
and fast as it can be melted in a cupola of the size they are 
using, to know that they are not using either too much or too 
little fuel in melting. 

If the foundryman will ask his neighbor what is the size of 
his cupola, how many tons does he melt per hour, how long 
does it take him to run ofT a heat, he will get a better guide to 
run his cupola by, than if he asks him how many pounds of 
iron he melts to the pound of fuel. As soon as the founder 
undertakes to imitate his neighbor and do faster melting or get 



CUPOLA MANAGEMENT. II5 

better results from his cupola, he will hear the old, old story 
from both melter and foreman: "We haven't enough blast." 
More cupolas have too much blast than too little, and the ap- 
parent deficiency of blast is due in the majority of cases to too 
much fuel in the cupola and the iron being melted only on the 
upper edge of the melting zone. It does not make any differ- 
ence how much or how little blast a cupola has. If it is given 
an even volume of blast throughout the heat, the cupola will 
melt a stream of iron of an even size and temperature through- 
out the heat except toward the end of a long heat, when the 
stream may get smaller. If the melter cannot run this kind of 
a stream through his cupola with an even blast, then he is at 
fault, and neither the blast, nor too much fuel, is the cause of 
the uneven melting. 

We have watched the charging of cupolas in a great many 
stove and machinery foundries, and as a rule more fuel is con- 
sumed in making dull iron in a machine foundry than is con- 
sumed in making hot iron in a stove foundry. This is simply 
because hot even iron cannot be produced with bad working of 
a cupola and too great a quantity of fuel, and the stove founder 
must have his cupola properly worked or he cannot use the 
iron to pour the work. 

TAPPING BARS. 

Tapping bars are made of round iron of from ^ to i inch 
diameter, and are from 3 to 10 feet long. The hand bars are 
made with an oval ring at one end to serve as a handle for 
rotating and withdrawing the bar when tapping. The other 
end is drawn down to a long, sharp point for cutting away the 
bod and making the tap hole. The bars for sledging are made 
straight with a long, sharp point at one end. This bar is only 
used in case the tap hole becomes so tightly closed that it can- 
not be opened with the hand bar, and seldom more than one is 
provided for a cupola. From three to six hand bars are pro- 
vided for each cupola, and when the ladles are all of the same 
size, the tap bars are all made of the same size, except one or 



Il6 THE CUPOLA FURNACE. 

two small ones which are provided for clearing the hole of any 
slag or dirt that may be carried into it by the iron. 

When the iron is melted for different sized work and large 
and small ladles are used, the bars are of dififerent sizes, so that 
a large or small hole may be made to suit the tap to be made 
or ladle to be filled. The bars are all straight except when the 
tapping is done from the side of a long spout. They are then 
slightly curved near the point, so that the hole can be made in 
a line with the spout. The bars are dressed and pointed at the 
forge before each heat, and are given any shape of point the 
melter may fancy. A square point cuts away a bod very rapidly 
when rotated and leaves a nice, clean hole, but it is very difificult 
to keep a point square, for it generally becomes round after 
a few taps have been made and it comes in contact with the 
molten iron a few times. For this reason the bars are gener- 
ally made round at the forge. 

Some melters have a short steel bar, with a sharp, flat point, 
which they use for cutting away the bod before tapping, but 
never use it for opening the hole. This they do to remove the 
greater part of the bod from the spout before tapping, and pre- 
vent it getting into the ladles. A hammer and an anvil, or an 
iron block, should be placed near the cupola for straightening 
the points and breaking cinder or dross from the bars, and a 
rack should be provided within easy reach of the tap hole^ 
in which to place the tap bars on end until wanted for use. 
There is nothing more slovenly and dangerous about a foundry 
than to have the tap bars lying around the floor when a heat 
is being run, and it is just as bad to set them up against a post 
from which they are all the time falling down. 

BOD STICKS. 

Two kinds of bod sticks are used for stopping in a cupola ; 
the wood stick and the combination wood and iron stick. 
The wood sticks are octagonal or round, from i ^^ to 2 inches 
diameter and from 5 to lo feet long. They are made of both 
hard and soft wood and about an equal number of each wood. 



CUPOLA MANAGEMENT. II7 

as some prefer one and some the other. When stopping in, 
the stick is held against the bod in the tap hole until it sets in 
the hole, and the stick generall)^ takes fire from the heat of the 
spout. On this account they soon become small near the ends 
and have to be sawed off; for this reason they are always made 
longer than necessary and sometimes larger in diameter. 

The combination stick is of the same diameter as the wood 
stick, and from 4 to 10 feet long. An iron ring is placed on 
one end of the stick, and a rod of round iron of from ^ to ^ 
inch diameter and I to 3 feet long is placed in the end. of the 
stick. On the end of the rod is placed a round button of from 
I ^ to 2 inches diameter, for carrying the bod. The object of 
the rod is to prevent the stick being burned by the heat of the 
spout every time the cupola is stopped in, and the length of the 
rod is made to correspond to the length of the spout. The 
objection to the combination stick is that the button does not 
carry the bod as well as the wood stick, and the button and rod 
must be wet every time the stick is used to keep it cool, or the 
heat will dry out the bod and it will fall off. This repeated 
wetting rusts the button, and if the edges come in contact with 
the molten iron it makes the iron sparkle and fly; and for this 
reason most founders prefer the wood sticks, even at the extra 
expense of keeping them up. 

An iron rod and button without the wood stick is also used 
in some foundries for stopping in, but they were not used by 
our grandfathers and are not popular with melters. Three or 
four bod sticks are provided for each cupola. They are placed 
on end in a rack alongside of the tap bars, within easy reach 
of the tap hole, and a bod is kept on each stick all the time 
the cupola is in blast. 

BOD MATERIAL. 

The bod is a plug used for closing the tap hole when it is 
desired to stop the flow of iron from a cupola, and the material 
of which the bod is composed has a great deal to do with the 
nice working of the tap hole. When the bod is composed of 



Il8 THE CUPOLA FURNACE. 

fire clay, or largely of fire clay, it does not give up the water of 
combination rapidly, and if a tap is quickly made after stopping 
in, the iron sputters and flies as it comes out of the hole. If 
the bod is permitted to become perfectly dry it bakes so hard 
that it cannot be cut away with the hand bar, and the heavy 
bar and sledge have to be used to make a hole of the proper 
size. If a friable sand is used it crumbles easily before the bar 
and a nice clean hole can be made ; but it does not hold well, 
and if the cupola is stopped in for any length of time the bod 
may be forced out by the pressure of metal. 

Some of the loams make an excellent bod that holds well 
and is easily cut away with the point of the bar, and leaves a 
clean hole. Some of the molding sands also make good 
bods in their native state, and there are several materials that 
are peculiar to certain localities that make good bods. When 
a suitable material cannot be found it must be made by mixing 
two or more materials. A good bod is made by mixing blue 
or yellow clay and molding sand. When these clays cannot be 
procured, a good bod can be made by mixing just enough fire 
clay with the molding sand to give it a little greater adhesive 
property, but not enough to make it bake hard. When a 
large body of iron is collected in the cupola before a tap is 
made, the bod material must be strong, and bake in the hole 
sufficiently hard to resist the pressure of the iron, and an entirely 
different material must be used for this kind of tapping than is 
used when the cupola is only stopped in for a few minutes at a 
time. 

Small cupolas from which only a small hand ladleful is drawn 
before it is stopped in also require a difTerent bod, for the hole 
has hardly time to clear itself before it is stopped in again, and 
if the bod burns hard or sticks in the hole, the hole is so hard 
to open that the small amount of iron is chilled by the bar and 
slow tapping before it can be run out. This kind of cupola 
requires a bod that will crumble and fall out as soon as touched, 
or burn out as soon as the hole is opened. A nice bod is made 
for this kind of work by mixing clay, molding sand and sawdust 



CUPOLA MANAGEMENT. II9 

and making it fully half sawdust. Blacking or sea coal is also 
mixed with bod material to make it more porous when burned 
and crumble more readily when tapping. 

Horse manure was at one time considered to be one of the 
essentials of a good bod, but it has been replaced by blacking 
or sawdust, and is seldom used. A good bod should have 
strength to resist the pressure of molten iron in the cupola and 
at the same time break away freely before the iron and leave a 
clean hole. Such a material can be made suitable for any 
cupola, no matter how it is tapped, and a bod material should 
never be used that requires the sledging tap bar to open the 
tap hole. 

TAPPING AND STOPPING IN. 

When the blast is put on the tap hole is generally open, and is 
left open until the iron melts and flows freely and hot from the 
hole. This is generally in from 5 to 20 minutes after the blast 
is on. While the melter is waiting for the iron, he arranges his 
tap bars, bod stufT and bod sticks, and places a bod on each 
stick to be ready for instant use. The bod material is worked 
a little wetter than molding sand to make it adhere to the end 
of the bod stick or button, but care must be taken not to have 
it too wet or it will make the iron fly when stopping in, and, 
furthermore, the bod does not hold well when too wet. The 
bod is made by taking a small handful of the bod stufT and 
pressing it firmly on the end of the stick with the hand. The 
size and shape the bod is made depend upon how the iron is 
tapped and the size of tap hole. When the hole is small and 
only stopped in for a few minutes at a time a small bod stick 
is used, and the bod made very small and shallow and only 
pressed into the hole a short distance, so that it can be quickly 
broken away when tapping. When the hole is large or has to 
be stopped in until a large body of iron collects in the cupola, 
the bod is made large, long and pointed, so that it may be 
pressed well back into the hole and stay in place until removed 
with the tap bar. 

The first iron melted flows from the hole in a small stream, 



120 THE CUPOLA FURNACE. 

and generally chills in the hole or spout and has to be removed 
with the tap bar; but it soon comes hot enough to clear the 
hole, which is then closed, unless the first iron is used to warm 
the ladles and the hole is kept open throughout the heat. If the 
work is light, a small tap is made in a few minutes to remove 
any iron that has been chilled and dulled by the dampness in 
the sand bottom. But when the work is heavy this tap is not 
made and the molders go on with their regular pouring from 
the start. The tap is made by placing the point of the bar 
against the bod and giving it a half forward and back rotation 
.and at the same time pressing it into the bod, or by carrying" 
the handle end of the bar around in a small circle and at the 
same time pressing it in. As soon as the bod is cut through, 
the bar is run into the hole once or twice and worked around 
a little to remove any of the bod that may be sticking round the 
sides of the hole. The bar must always be held in such a posi- 
tion as will make the hole in a line with the spout, or the 
stream will not flow smoothly and may shoot over the sides of 
the spout and burn the men catching in. 

When about to stop in, the bod is placed directly over the 
stream close to the tap hole and the other end of the stick is 
elevated at a sharp angle from the spout. The hole is closed 
by a quick downward and forward movement of the stick that 
forces the bod into the hole and checks the stream at once. 
The stick is then held against the bod for a few seconds until 
the force of the stream is stopped and the heat has set the bod 
fast in the hole. The part of the bod that does not enter the 
hole is then removed with the stick to keep the spout clean, 
and the stick is dipped in water to cool it, and another bod 
applied to be ready for the next time. There is a great knack 
in stopping in, that some melters never acquire. They hold 
the bod too far from the hole, and attempt to push it up, under 
or through the stream ; they get nervous and are not sure of 
their aim and strike the stream too soon, or the side of the 
hole, and the iron sputters and flies in :all directions. 

The bod sticks are frequently made so long and slender or 



CUPOLA MANAGEMENT. 12 1 

SO heavy that it is impossible to accurately place the bod, and 
it is sometimes difificult to get the cupola stopped in with these 
long sticks. It is also difficult to stop in when the cupola is 
placed very high, for the melter cannot get up to place the bod 
stick at a proper angle for stopping in, and has to run the bod 
up through the stream, in place of cutting ofif the stream with 
the bod. An arm or bracket is sometimes placed over the 
spout near the tap hole, when long bars and sticks are used, 
upon which to rest the tap bars and bod sticks when tapping 
and stopping in. But a better plan is to construct a movable 
platform that can be placed alongside the spout for the melter 
to stand on. He can then use short bars and sticks, and has 
much better control of the tap hole than with the long bars 
and sticks. 

At the tap hole is seen the skill of the melter in the results 
obtained from his labor. If the bed has been burned too much 
the first charge comes down fast or slack or dull. If the bed 
is too high the first iron is a long time in coming down. If too 
much fuel is used, the iron melts slowly and is dull toward the 
last if the heat is long. If the charges of iron are too heavy, 
the iron comes dull at the end of each charge. If the charges 
of fuel are too large, there is slow melting at the end of each 
charge. If the iron flows from the tap hole with great force 
and is difficult to control, the sand bottom has too much pitch. 
If slag flows freely from the tap hole with the iron, the hole 
is too large or the bottom has too much pitch. If the spout 
melts, crumbles or chips ofT, the material is poor or has not 
been properly mixed. If the tap hole cuts out, the material is 
poor or the tap hole has not been properly made. If the tap 
hole gums up and cannot be kept open, the front material is 
poor and is melted by the heat, and it may also be melted b}- 
the heat when it is good if rammed soft and ragged inside. If 
the tap hole cannot be opened without a sledge and bar, the 
bod bakes too hard and the material should be changed. If 
the bod does not hold, the material is not good or the bod is 
not put in right. If the cupola does not melt evenly through- 



122 THE CUPOLA FURNACE. 

out the heat and the same every heat, it is the fault of the 
melter and not of the cupola. 

DUMPING. 

As soon as the molders are through pouring their work, if 
there is no iron to be melted for other purposes, preparations 
are at once m.ade for dumping the refuse from the cupola. 
The blast is first shut off by stopping the blower and the 
tuyere doors are at once opened to prevent the escape of gas 
from the cupola into the blast pipe, where it might do much 
harm. The melted iron in the cupola is then drawn ofif by the 
cupola men and poured in the pig bed. If there is a lot of 
small iron in the cupola that has not been melted time is given 
it to melt to save picking it out of the dump, but if there is a 
lot of pig or other heavy iron unmelted it is let fall with the 
dump, and the bottom is dropped as soon as the melted iron 
is drawn ofT. 

The small props supporting the bottom are first removed 
and laid away. The main prop is then removed by striking it 
with a long bar at the top or pulling with a hooked bar at the 
bottom, and the instant it falls the doors drop. When the 
doors of a large cupola drop, the sand bottom and a greater 
part of the refuse of melting falls with them and a sheet of 
flame and dust instantly shoots out ten feet or more from the 
bottom of the cupola in all directions. But the flame dis- 
appears in an instant and the dust settles, revealing the white 
hot dump in a heap under the cupola. The cupola men then 
throw a few buckets of water on it to chill the surface and 
deaden the heat, and the melter puts a long bar into the tuyeres 
and tries to dislodge any refuse that may be hanging to the 
lining while it is hot. Small cupolas do not dump so freely, 
and the sand bottom has frequently to be started with a bar 
after the door drops. A long bar must be used for this pur- 
pose, and the melter must be on his guard, for the dump may 
fall as free as from a large cupola the instant it is started and a 
sheet of flame shoots out. 



CUPOLA MANAGEMENT. 1 23 

Small cupolas frequently bridge over above the tuyeres, and 
only the sand bottom and refuse below the bridge are dumped 
when the door falls. The aim of the melter is then to break 
away the bridge or get a hole through it, so that the cupola will 
cool ofT in time to be made ready for the next heat. He puts 
a bar in at the tuyeres and breaks away small pieces at a time, 
and if there is not a large body of refuse in the cupola, a few 
short pieces of pig are thrown in from the charging door, so 
that they will strike in the center and break through the bridge. 
This bridging and hanging up of the refuse in a cupola when 
only run for a few hours is entirely due to mismanagement, for 
any cupola, no matter how small it may be, can be run for six 
or eight hours without bridging and be dumped clean if prop- 
erly worked. 

When the dump falls from a cupola it is a semi-fluid mass of 
iron, slag, cinder, dirt and fuel. This mass falls in a heap 
under the cupola, and if scattered or broken up when very hot 
it is more readily wet down and more easily removed when 
cold. In some foundries a heavy iron hook or frame is placed 
under the cupola before dumping and is withdrawn with a chain 
and windlass after the dump has fallen upon it and been par- 
tially cooled with water to harden it so that the hook will not 
slip through it without breaking it up and scattering it. In 
other foundries it js scattered with a long rake or hook worked 
by hand. In pipe foundries two or three short lengths of con- 
demned pipe are placed under the cupola before dumping, and 
the dimip is broken up by running a bar into the pipe and lift- 
ing it up after the dump has been slightly cooled. But in a 
great many foundries where the dump is small or where there 
is plenty of room to remove it when cold, it is left lie as it falls 
and is wet down by the cupola men, or a few buckets of water 
are thrown on by the cupola men to deaden it, and it is left for 
the watchman to wet down during the night. Care must be 
taken not to use too much water, or the floor under the cupola 
will be made so wet that there will be danger of the dump 
exploding when it falls upon it the next heat. 



124 'fHE CUPOLA FURNACE. 

REMOVING THE DUMP. 

A number of plans have been devised for removing the dump 
from under the cupola. Iron cars or trucks have been con- 
structed to run under the cupola and receive the dump as it 
falls, but they cannot be used unless there is sufficient room for 
the doors to swing clear of the car, and few cupolas are so con- 
structed. The dump must be removed from the car when hot 
to avoid heating and injuring the car, and considerable room is 
required for handling the car after it is taken from under the 
cupola. For these reasons cars are seldom used. Iron crates 
have been made to set under the cupola and receive the dump 
and be swung out with the crane, but they get fast under the 
cupola and are soon broken, and it is almost as much work to 
handle the dump from the crane as it is from under the cupola. 
A number of other plans have been tried, but the dump must 
be picked over by hand, and it is as cheap to pick it over at 
the cupola and remove it in wheelbarrows as by any way that 
has yet been devised. The dump is broken up with sledge and 
bar when cold and picked over. The large pieces of iron are 
picked out and thrown in a pile for remelting. The coke is 
thrown in a pile to be taken to the scafTold or core oven fur- 
nace. Anthracite coal that has passed through a cupola and 
been subjected to a high heat will not burn alone in a stove or 
core oven furnace, and it is very doubtful if it produces any 
heat when mixed with other coal and again put in the cupola, 
and only the large pieces are picked out, if any. 

The cinder, slag and other refuse are shoveled into a wheel- 
barrow and taken to the rattle-barrels or dump. If the sand 
bottom is to be used over again it is riddled out in a pile and 
wetted. If not, it is removed with the cinder and slag. As 
soon as the bulk of the dump is removed the melter goes into 
the cupola and breaks down the ring of cinder over the tuyeres 
and chips off any that may be adhering to other parts of the 
lining. The dump is then all removed and the floor around the 
cupola is cleaned up preparatory to daubing up. Nothing is 
done with the dump after it is taken from the cupola but to 



CUPOLA MANAGEMENT. I 25 

recover the iron from it. This is done in two ways, by picking 
it over or milling it. The iron is often of the same color as the 
dump, and so mixed with it that it is almost impossible to re- 
cover it all by picking unless a great deal of time and pains be 
taken ; and it is cheaper to throw out only the pieces of pig 
and shovel all the remainder into the tumbling barrels, where 
it is separated in a short time and all the iron recovered that is 
worth recovering. 

CHIPPING OUT, 

Before going into the cupola to chip it out the melter slushes 
one or two buckets of water around the lining from the charging 
door to lay the dust. He then goes in from the bottom if he 
can get in, but if the cupola is so badly bridged that he cannot 
get up into it, he takes a long bar and endeavors to break down 
the bridge from the charging door, or goes down into it from 
the charging door, and with a heavy bar or sledge breaks it 
down. As soon as he gets a hole through large enough to 
work in, he goes down through it and with a sledge or heavy 
pick breaks down the shelf of slag and cinder that always pro- 
jects from the lining over the tuyeres. He then takes a sharp 
pick and trims ofT all projecting lumps of cinder and slag and 
gives the lining the proper shape for daubing up. It is not 
necessary or advisable to chip off all the cinder and adherent 
matter down to the brick, for the cinder stands the heat equally 
as well as new daubing, and in some cases better. But all soft 
honeycombed cinder should be chipped off, and all projections 
of hard cinder that are likely to interfere with the melting or 
tend to cause bridging should be removed. 

Some melters have a theory that to prevent iron running into 
the tuyeres they must have a projection or hump on the lining 
over the tuyeres, and they let the cinder build out from 3 to 6 
inches thick and 6 to 12 inches deep at the base. These humps 
tend rather to throw iron into the tuyere than to keep it out, 
for the fuel becomes dead under the hump and the iron in its 
descent strikes the hump and follows it around into the tuyere. 
They also form a nucleus for bridging. The refuse of melting 



126 THE CUPOLA FURNACE. 

as it settles lodges upon these humps and is chilled by the 
blast. A small cupola with these humps over the tuyeres will 
not work free for more than an hour, while the same cupola 
with the humps removed and the lining straight would work 
free for two hours and dump clean. They also interfere with 
the melting and in large cupolas cause bridging. All humps 
that form on the lining above the melting point from bad 
charging or other causes should be removed, for they hang up 
the stock and retard melting. 

The cupola picks generally used are entirely too light for the 
work to be done with them, and the handles are not firm 
enough. When the melter strikes a blow he cannot give the 
pick force enough to cut away the point desired and the handle 
gives in the eye, so that the pick glances off and cannot be 
held to the work. Repeated blows with a light pick turn the 
edge and render the pick worthless and the melter has to do 
two or three times the work really necessary in chipping out 
the cupola, and then he does not get it right. What the melter 
wants is a heavy pick with a firm handle. Then he can hold 
the pick where he strikes and prevent it glancing off. He can 
strike a blow that will cut away the cinder at one stroke and 
not jar and injure the lining nearly so much as he would by 
repeated blows with a light dull pick. The melter should be 
provided with three picks made of the best steel, weighing 4, 
6 and 8 pounds each. They should be furnished with iron 
handles solidly riveted in, or should be made with large eyes 
for strong wood handles. The picks should be dressed, tem- 
pered and ground as often as they get the least bit dull, 

DAUBING. 

After the cupola is chipped out the lining is repaired with a 
soft plastic adhesive material known as daubing, with which all 
the holes that have been burned in the lining are filled up and 
thin places covered, and the lining given the best possible shape 
for melting and dumping. There are a number of substances 
used for this purpose, some of which are very refractory, and 



CUPOLA MANAGEMENT. I 27 

others possess scarcely any refractory properties whatever and 
are not at all suitable for the purpose. Molding sand is fre- 
quently used for a daubing. It is easily and quickly wet up 
and mixed, is very plastic and readily put on, but possesses 
none of the properties whatever requisite to a good daubing. 
It crumbles and falls off as soon as dry in exposed places, and 
a lining cannot be shaped with it. Furthermore, when put on 
in places from which it is not dislodged in throwing in the 
stock, it melts and runs down and retards the melting by mak- 
ing a thick slag that is readily chilled over the tuyeres by the 
cold blast. 

Some of the yellow and blue clays are very adhesive and re- 
fractory, and make good daubing alone or when mixed with a 
refractory sand. Ground soapstone and some of the soapstone 
clays from coal mines make excellent daubing. But probably 
the best and most extensively used is that composed of fire 
clay and one of the silica sands known under various names in 
difTerent sections of the country, and which we shall designate 
sharp sand. Fire clay is very plastic and adhesive when wet, 
but shrinks and cracks when dried rapidly. Sharp sand alone 
possesses no plastic or adhesive properties whatever and ex- 
pands when heated. When these two substances, in exactly 
the right proportions, are thoroughly mixed, they make a daub- 
ing that is very plastic and adhesive, does not crack in drying, 
neither expands nor shrinks to any extent when heated, and 
resists the action of heat as well as fire-brick in a cupola. 
When not evenly mixed the fire clay cracks and the sand ex- 
pands and falls out of the clay when heated, making an uneven 
and uncertain daubing. 

Fire clay absorbs water very slowly, and it requires from 12 
to 24 hours' soaking before it becomes sufficiently soft to be 
thoroughly and evenly mixed with the sand. A large soaking 
tub should be provided near the cupola and it should be filled 
with clay every day after the cupola is made up, and the clay 
covered with water and left to soak until the next heat. The 
clay and sand cannot be evenly mixed in a round tub with a 



128 THE CUPOLA FURNACE. 

shovel, therefore a long box and a good strong hoe should be 
provided for the purpose. The amount of sand a clay requires 
to make a good daubing varies from one-fourth to three-fourths, 
according to the qualities of the clay and sand, but generally 
one-half of each gives good results. The sand is added to the 
clay dry, or nearly dry, and the daubing is made as thick and 
stifT as it can be applied to the lining and be made to stick. 
The more it is worked in mixing the better, and if let lie in the 
mixing box for a day or two after mixing it makes a better 
dauliing than if applied as soon as prepared. 

Nothing is gained by using a poor, cheap daubing, for it 
does not protect the brick lining, but falls ofT or melts into a 
thick tough slag which runs down and chills over the tuyeres 
and retards the melting by bunging up the cupola, and more 
fuel and time are required to run ofif the heat. The daubing is 
taken from the mixing box on a shovel when wanted for daub- 
ing and placed on a board under the cupola if the box is near 
at hand. When it is some distance from the cupola the daub- 
ing is placed in buckets or small boxes made for the purpose 
and conveyed to the cupola. The parts of the lining to be re- 
paired are first brushed over with a wet brush to remove the dust 
and wet the lining so that the daubing will stick better. The 
daubing is then thrown on to the lining with the hands in small 
handfuls; it can be made to penetrate the cracks and holes 
better in this way than in any other, and stick better than when 
plastered on with a tfowel. After the required amount has 
been thrown on in this manner, it is smoothed over with a trowel 
or wet brush and made as smooth as possible. 

SHAPING THE LINING. 

Daubing is applied to a lining for two purposes — viz,, to 
protect the lining and to shape the cupola, the latter being by 
far the most important of the two. A great many melters 
never pay any attention to it, their only aim being to keep up 
the lining, and they pride themselves on making a lining last 
for one, two or three years. Nothing is gained by doing this 



CUPOLA MANAGEMENT. 129 

if the melting is retarded by doing so and enough fuel con- 
sumed and time and power wasted every month to pay for a 
new lining. Besides, a lining will last just as long when kept 
in good shape for melting as when kept in a poor one, and the 
aim of the melter should be to put the lining in the best possi- 
ble shape for melting and make it last as long as he can. 

New linings are made straight from the bottom plate to the 
charging door when the cupola is not boshed. When it is 
boshed the cupola is made of smaller diameter at and below 
the tuyeres, and the lining is sloped back to a larger diameter 
from about 6 inches above the tuyeres, with a long slope of i8 
or 20 inches. In the straight cupola, slag and cinder adhere 
in every heat to the lining just over the tuyeres, and if not 
chipped off close to the brick after each heat, gradually build 
out and in time a hard ledge forms that is difficult to remove. 
It furthermore reduces the melting capacity of the cupola by 
increasing the tendency to bridge. Above this point at the 
melting zone the lining burns away very rapidly and in every 
heat a hollow or belly is burned in at this point that requires 
repairing. Above the melting zone the lining burns away very 
slowly and evenly and seldom requires any repairing until it 
becomes so thin that it has to be replaced with a new one. 

The cinder and slag that adhere to the lining just over the 
tuyeres must be chipped off close to the brick every heat, and 
the lining made straight from the bottom plate to 6 inches 
above the top of the tuyeres. No projection or hump of more 
than ^ or ^ inch should ever be permitted to form or be 
made over the tuyeres to prevent iron running into them, and 
it should be placed right at the edge of the tuyeres when it is 
thought necessary to make it. The upper edge of the tuyere 
lining should be made to project out a little further than the 
lower edge, and the brick lining should be cut away a little 
under each tuyere so that molten iron falling from the top of 
the tuyere will fall clear of the bottom side of the tuyere and 
not run into it. 

It is not necessary or advisable to fill in the lining at the 

9 



I30 THE CUPOLA FURNACE. 

melting zone and make it perfectly straight, as it is when it is 
new, for a cupola melts better when bellied out at the melting 
zone. It must, however, be filled in to a sufificient extent for 
each heat to keep up the lining and prevent it being burned 
away to the casing. No sudden offsets or projections should 
be permitted to form or remain at the upper edge of the melt- 
ing zone, for the stock lodges in settling upon projections and 
does not expand or spread out to fill a sudden ofifset, and so 
the heat passes up between the stock and lining and cuts away 
the lining very rapidly. No sudden ofifset or hollow should be 
permitted to form at the lower edge of the melting zone over 
the tuyeres, for the stock will lodge on it in settling and cause 
bridging of the cupola. The lining should be given a long 
taper from 6 inches above the tuyeres to the middle of the 
melting zone, and a reverse taper from there to the top of the 
melting zone. The belly in the lining should be made of an 
oval shape, so that the stock will expand and fill it as it settles 
from the top, and not lodge at the bottom as it sinks down in 
melting. As the lining burns away above the melting zone 
the straight cupola assumes the shape of the boshed cupola, 
and only the lower taper is given to the melting zone. 

Daubing should never be put on a lining more than i inch 
thick, except to fill up small holes, and even then small pieces 
of fire brick should be pressed into it to reduce the quantity of 
daubing and make it firmer. All clays dry slowly and give up 
their water of combination only when heated to a high temper- 
ature. When daubing is put on very thick it is only skin-dried 
by the heat of the bed before the blast goes on. The intense 
heat created by the blast glazes the outside of the daubing be- 
fore it is dried through to the lining, and as there is no way for 
the moisture to escape, it is forced back to the lining, where it 
is converted into steam and in escaping shatters the daubing 
or tears it loose from the lining at the top. 

In the accompanying illustration. Fig. 27, is shown a sec- 
tional view of a cupola that we saw at Richmond, Ind., in 1875 
This cupola was a small one, about 35 inches diameter at the 



CUFOI.A MANAGEMENT. 



131 



tuyeres, and the average heat was about 4 tons. The melter 
was a hard-working German, who knew nothing about meUing 
whatever, and his only aim was to keep up the lining in the 
cupola. With this object in view he would fill in the hollow 
formed in the lining every heat at the melting zone with a 

Fig. 27. 




SECTION THKOUGH BRIDGED CUPOLA. 



daubing of common yellow clay and make the lining straight 
from the tuyeres up. The daubing required to do this was 
from 2 to 4 inches thick all around the cupola, and was put on 
very wet. The heat dried and glazed this daubing on the out- 
side before it was dried through. There being no way for the 



132 THE CUPOLA FURNACE. 

water to escape, it was converted into steam, and in escaping 
from behind the daubing tore it loose from the lining at the 
top. The fuel and stock in settling got down behind the daub- 
ing and pressed it out into the cupola from the lining until it 
formed a complete bridge, with only a small opening in the 
center through which the blast passed up into the stock. Be- 
fore the heat was half over all the iron melted was running out 
at the tuyeres, and the bottom had to be dropped. When the 
cupola had cooled ofif, the daubing and stock were found in the 
shape shown in the illustration, and when the bridge was broken 
down it was found to be composed entirely of daubing that had 
broken loose from the lining in a sheet and doubled over. 

This melter always had slow melting and difficulty in dump- 
ing. Some nights after dumping he would work at the tuyeres 
with a bar until eight o'clock before he got a hole through, so 
the cupola would cool off by morning. The lining was not 
protected by the thick daubing, but was cut out more by the 
repeated bridging than if it had been properly coated with a 
thin daubing. We daubed this cupola properly and ran off 
two heats in it and melted the iron in less than half the time 
usually taken, and had no difficulty in dumping clean. 

The lining of the boshed cupola does not burn out at the 
melting zone in the same shape nor to so great an extent as in 
the straight-lined cupola, and in shaping the lining it is made 
almost straight from the top of the slope to the bosh up to the 
charging door. The taper from the bosh to the lining should 
start at 6 inches above the top of the tuyeres, and should not 
be less than 18 or 20 inches long, and must be made smooth 
with a regular taper so that the stock will not lodge on it in 
settling. Should the cupola be a small one with a thick lining 
and only slightly boshed and burn out at the melting zone 
similar to the straight cupola, it must be made up in the same 
way as the straight cupola. The great trouble with boshed 
cupolas is that the melter does not give a proper slope to the 
taper from the bosh, but permits a hollow to form in the lining 
over the tuyeres, in which the stock lodges in settling and 
causes bridging out over the tuyeres. 



CUPOLA MANAGEMENT. I 33 

These directions for shaping the lining only apply to the 
common straight and boshed cupolas. Many of the patent 
and odd-shaped cupolas require special directions for shaping 
and keeping up the lining as it burns out, and every manufac- 
turer of such cupolas should furnish a framed blueprint or 
other drawing, to be hung up near the cupola, showing the 
shape of the lining when new and the shape it should be put in 
as it burns away and becomes thin. Full printed directions 
should be given for chipping out and shaping the lining. All 
the improvements in cupolas are based on the arrangement of 
the tuyeres and shape of the lining, and when the lining gets 
out of shape the working of the tuyeres is disarranged, and the 
cupola is neither an improved nor an old style one, and is gen- 
erally worse than either. More of the improved cupolas have 
been condemned and thrown out for want of drawings showing 
the shape of the lining and directions for keeping it up, than 
for any other cause. 

RELINING AND REPAIRING. 

When a cupola is newly lined the lining is generally made of 
the same thickness from the bottom to the top except when the 
cupola is boshed. The casing is then either contracted to form 
the bosh or it is formed by putting in two or more courses of 
brick at this point. The lining varies in thickness from 4^ to 
12 inches, according to the size of the cupola, the heavier 
linings always being put in large cupolas. The greatest wear 
on the lining is at the melting zone, where it burns away very 
rapidly. From this point up it burns away more gradually and 
evenly, but the greatest wear is toward the bottom, where the 
heat is the greatest, and so a cupola gradually assumes a funnel 
shape with the largest end down and terminating at the melt- 
ing zone, and the lining is always thinnest at about this point 
when it has been in use for some time. 

At and below the tuyeres the destruction of the lining by 
heat is very slight, and the principal wear is from chipping and 
jarring in making up the cupola. At the charging door the 



134 THE CUFOLA FURNACE. 

principal wear is from the stock striking the lining in charging. 
In the stack the lining becomes coated with sulphides and 
oxides and is but little affected by the heat. A stack lined 
with good material properly put in generally lasts the lifetime 
of the cupola. The length of time a cupola lining will last de- 
pends upon the amount of iron melted and the way in which it 
is taken care of, and varies from six months to three or four 
years when the cupola is in constant use. 

A lining burns away very rapidly at the melting zone, and if 
not repaired every heat would burn out to the casing in a few 
heats. Above the melting zone it burns away more slowly and 
evenly, and gets thinnest just above the melting point. From 
this point it gradually grows thicker up toward the charging 
door, where the wear is comparatively slight. The thickness 
of lining required to protect the casing where the heat is most 
intense depends upon the quality of the fire brick and how the 
lining is put in. A lining of good circular brick made to fit 
the casing, and laid up with a good, well-mixed grout, remains 
perfectly solid in the cupola as long as it lasts, and may be 
burned down to [ ^ inches in thickness, and even less, for 
several feet above the melting point. When the bricks do not 
fit the casing and large cracks or holes have to be filled in with 
grout, and daubing or the lining is poorly laid up, it becomes 
shaky as it burns out and in danger of falling out, and it cannot 
be burned down so thin as when solid. 

It is therefore cheaper in the long run to get brick to fit the 
the casing and have the lining well put in. It will then only be 
necessary to reline when the lining gets very thin almost up to 
the charging door. The lining at the melting zone, where it 
burns away the fastest, is often taken out for 2 or 3 feet above 
the tuyeres and replaced with a new one when it is not neces- 
sary to reline all the way up. In repairing a lining in this way 
the same sized bricks are generally used as were used in lining. 
The lining has been burned or worn away above and below the 
point repaired, and the new lining reduces the diameter of the 
cupola to the smallest at the very part where it should be the 



CUPOLA MANAGEMENT. I 35 

largest. The result is that the new lining is cut away faster 
than any other part, and after a few heats it is as bad as it was 
before the new section was put in. 

A better way of repairing a lining at the melting zone is to 
put in a false lining over the old lining. This is done by putting 
on a layer of rather thin plastic daubing over the old lining and 
pressing a split fire-brick into the daubing with the flat side 
against the lining. The bricks are pressed into the daubing 
close together almost as soon as it is put on, and all the joints 
are filled up and the surface made smooth. A lining may be 
put in a cupola in this manner all the way around and to any 
height desired, or only thin places may be repaired, which is 
done without forming humps in the lining that interfere with 
the melting. 

A split brick is an ordinary fire-brick, only i inch thick in 
place of 2 inches, and is now made by all the leading fire-brick 
manufacturers. We believe we were the first to repair a lining 
in this way, some 30 years ago. The split brick could not then 
be procured from fire-brick manufacturers, and they were made 
by splitting the regular sized brick with a sharp chisel after 
carefully nicking them all around. When the regular split 
brick cannot be procured they may- be made in this way. 
Most of the new brick split very readily and true, but bats from 
old lining generally spall off and are dif^cult to split. A lining 
of split brick can be put in almost as rapidly as the cupola can 
be shaped with daubing alone. The diameter of the cupola is 
not reduced to the same extent as with a section of new lining 
put in in the regular way, and the best melting shape for the 
cupola is maintained with only a reduction in the diameter of 
from 3 to 4 inches. This lining, when put in with a good daub- 
ing well mixed, lasts as long as an equal thickness of lining put 
in in the regular way; and it can be put in at a great deal less 
expense for labor and material. It is, however, worthless if 
put in with a poor, non-adhesive and unrefractory daubing. 

An excellent daubing material may be made from the pieces 
of fire-brick removed from the cupola when relining, by plac- 



136 THE CUPOLA FURNACE. 

ing them in an ordinary tumbling barrel with a few pieces of 
pig iron. The weight of the iron in tumbling soon reduces 
the brick to a fine powder, which passes through the staves 
and may be recovered from under the mill. This powder when 
mixed with a sufficient quantity of clay to render it adhesive 
makes the best of daubing material for cupolas, and a thinner 
daubing for large ladles may be put on of this material with 
safety than of any other kind. 



CHAPTER VI. 

MODERN CUPOLAS. * 

The cupolas described below may be classed as modern or 
standard, although some of them have been made and placed 
upon the market by manufacturers for many years. They all 
have the desirable features in cupola construction of high charg- 
ing doors and abundant tuyere area, and in general construction 
only differ in minor points. It is interesting to note that the 
belt air chamber extending down to the bottom plate, designed 
by Mr. Colliau for the purpose of giving a hot blast to a cupola, 
is giving way to the more rational design of the belt air cham- 
ber seen in the illustration of the Newten Cupola (Fig. 30), and 
that the double and triple rows of tuyeres, also introduced in 
this country by Mr. Colliau, are being abandoned, especially 
for small cupolas, and only the single row is used. 

Many founders do not seem to realize the importance of high 
cupolas for fast and economical melting, and when installing a 
new cupola in their plant have the charging door placed at a 
height to suit the scaffold used for the old cupola, which was 
probably of the low cupola design of many years ago. All 
manufacturers of standard cupolas have a rule for the height of 
the cupola in proportion to its diameter. This rule should be 
strictly adhered to if the best results in melting are to be ob- 
tained, and the scafifold raised to suit a proper construction of 
the new cupola. 

COLLIAU CUPOLAS. 

The Colliau Cupola was designed and manufactured by the 
late Victor Colliau, who spent much time and thought in the 
improvement of cupolas, and to whom is due the credit of the 
present fast and continuous melting in cupolas, at least in this 

(137) 



138 THE CUPOLA FURNACE. 

country; for he was the first to introduce the double row of 
tuyeres for rapid melting, and the tapping of slag for con- 
tinuous melting. The general outlines in construction of this 
cupola are shown in Figs. 28 and 29, which is now manufac- 
tured by Mr. Colliau's former partners, Messrs. Bryam and Co. 
The only difference in general outline of construction between 
this cupola and his later design was in extending the belt air 
chamber from the bottom plate up to near the charging door 
for the purpose of heating the blast by heat escaping through 
the caisson. This arrangement and construction he designated 
a hot blast cupola, but it proved a hot blast in name only, and 
after a few of them had been placed in foundries and proved 
failures in heating the blast, this plan of construction was 
abandoned and his cupola constructed upon the plan show^n 
in the illustrations. After the death of Mr. ColliaUs his cupola 
business was entirely wound up, and the only Colliau cupolas 
now obtainable are those manufactured by other firms. 

STANDARD COLLIAU CUPOLA FURNACE. 

In Figs. 28 and 29 are shown external and sectional views 
of the Colliau cupola as originally designed by Mr. Colliau and 
now manufactured by his former partners. The following short 
description is from their circular: 

The Colliau is made in three distinct parts, so that parties 
desiring to make only a small outlay and at the same time 
secure the benefit arising from use of the Colliau may order 
only the lower part with air chamber tuyeres and melting zone, 
which constitute the essential parts and may be used with any 
suitable "stack" and "foundation." 

The lower portion of the Colliau is composed of two sheet- 
steel shells, the inner shell being made very heavy and of the 
same size as the stack proper. The outer shell encircles the 
inner one and is made air-tight, forming the air chamber, which 
varies in size according to size of furnace. In the outer shell 
are arranged two doors or shutters held in position by tap 
bolts, also made air-tight, which may be removed and be again 



MODERN CUPOLAS. 



139 



replaced after cleaning, should any coke or slag accumulate in 
the air chamber. 

Fig. 28. 




COLLIAU til"! \. 



I40 



THE CUPOLA FURNACE. 



"Besides this," say the manufacturers, " we place a hand 
hole plate in the outer shell of air chamber directly under each 
lower tuyere, held in position by crab and bolt. Our air 
chamber is not fastened to the bottom plate, but is separate 
and distinct, and is air-ti:^ht in itself. 



Fig. 29. 



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" Opposite each tuyere also is a sliding air-tight gate with 
peep hole, and in the beveled top is furnished a brass nipple to 
connect hose from the blast meter into the air chamber. 

" Our present tuyeres are of the latest and most approved 
patterns, so arranged that the blast is distributed over the 



MODERN CUPOLAS. I4I 

entire area of the combustion chamber, and are constructed in 
such form that the melted iron in its downward course cannot 
pas^ through them into the air chamber. If desired, these 
lower tuyeres can be made adjustable in height. 

"The Bottom Plate of each furnace is made in four (4) 
pieces, with joint over each leg, at which point it is reinforced 
by a steel plate. This arrangement permits of the necessary 
expansion and contraction without the possibility of cracking. 

" Each furnace is provided with a metal alarm and trap with 
fusible disc. 

"The furnace, as a whole, is simple in its construction. 
There is no complicated machinery or parts to get out of order, 
and consequently does not require any more attention or re- 
pairs than a common cupola. 

" In large shops, and where a large number of hands are em- 
ployed, the most important factor in melting iron is the rapidity 
with which it can be done. 

" The records of * the Colliau ' in this respect have never 
been excelled. 

" The Cupola can be operated by unskilled workmen, if in- 
structions are followed." 

THE NKWTON CUPOLA. 

The Newton Cupola, Fig. 30, while of modern design and 
fully up-to-date, reminds one of the days of the common, 
straight, plain cupola, when iron was supposed to be melted in 
a cupola and drawn from the tap-hole and not from the wind 
box. 

Mr. Newten. the designer of this cupola, evidently under- 
stood that melting is done inside of a cupola and not on the 
outside, for he has not devoted all his attention to the de- 
signing and construction of a wind box with elaborate air-tight 
hand-holes and openings for removing iron and slag from it, 
nor to the making of a cupola as big as a blast furnace or to 
resemble one by nonsensical outside attachments. But he has 
given to the outside a neat eupola-Iike appearance, while re- 



142 



THIC CUPOLA FURNACE. 



taining all the modern inside improvements in construction, 
arrangement of tuyeres, safety tuyere, slag-hole, etc. 

Fic. 30. 




THE NEWTEN CUPULA. 



MODERN CUPOLAS. I 43 

The following is part of what the manufacturers have to say 
about it: 

"The Tuyere System, which is patented, is in accord with 
the best practical arid theoretical modern cupola practice. 

" The combined tuyere area is the important consideration, 
and the exact proportion which the areas of tuyeres, blast pipe 
and air chamber bear to the size of the furnace and the 
blower has been carefully adjusted to obtain the best melting 
speed and the most economical fuel results. 

''The Main Tuyeres are of the expanded type, both inlet 
and outlet being of ample area to secure the transmission of 
sufficient air to the furnace. The increase in the area of the 
greatest portion of the tuyeres as they approach the fuel se- 
cures a blast of large volume and of moderate pressure nearest 
the iron, and the wide tuyeres afford nearly a continuous blast 
opening around the furnace walls. By these m.eans ample blast 
area is assured, even if a portion of the tuyere area is stopped 
by pieces of coke or other obstructions. 

" The lower tuyeres are adjustable vertically, through several 
inches, to suit either a deep or a shallow bed of fuel. This adapts 
the furnace to either coke or coal, or to any change in the inside 
diameter of the furnace, to suit different classes of work. 

" One tuyere has a low spout connected with a soft metal 
])lug; this is burned out and gives warning if the molten iron 
should rise too high. 

"The upper tuyeres are fitted with dampers enabling them 
to be closed if desired ; the main tuyeres having ample area 
for the required capacity. 

"Special attention has been given to methods of getting the 
blast to the fuel in the most direct and efficient manner. 

"The entire body of the air chamber — bottom, top and sides 
— is made of plate steel, flanged, riveted and caulked, insuring 
an air-tight construction. 

"The blast enters the air chamber through a single inlet, 
which branches to right and left, giving a tangential motion to 
the blast in both directions. 



144 THE CUPOLA FURNACE. 

"The bottom of the air chamber is raised several inches 
above the bottom plate to afford free inspection of the bottom 
of the shell at all times, it being at this point that cupola shells 
most frequently fail through rust. 

" The bottom plate is very thick, and is heavily ribbed ; a 
flange extending around the entire shell. 

"Bottom doors are of the hinged- drop type, with perforated 
plate and four heavy ribs on each door. On large cupolas 
there is provision for the attachment of levers for lifting doors 
into place. 

" A slag opening is located below the lower tuyeres, its 
height being adjustable to suit conditions. It is fitted with a 
suitable slag spout. By using the slag hole, the cupola can be 
kept from clogging, and continuous melting for a long period 
will result. 

"The charging door is extra large. The frame has a heavy 
iron slide at its base, protecting the lining. The charging doors 
may be either of the plate type for brick or mud lining, or of the 
wire screen type, the former being used unless otherwise or- 
dered. Two charging door openings or frames are provided 
on all cupolas left larger than ']2 inches. 

" Our No. 30 Cupola is often sold as a test cupola, for work 
at technical schools, or in large plants for testing quality of 
iron. It can be mounted either on trunnions or on columns in 
the regular way. 

" In this cupola but two large tuyeres are used, and the air is 
carried direct to the tuyeres from a branched blast pipe, the 
standard air chamber being omitted." 

PAXSON COLLIAU CUPOLA. 

In Figs. 31, 32 are seen external and sectional views of the 
Paxson Colliau cupola, illustrating the two zones of melting as 
designed by Mr. Colliau, but changed in some important details 
in construction in this cupola, to bring it fully up to date as a 
latest improved cupola. The lower tuyeres are rectangular 
and flared, and the upper ones are oval. They are staggered 



MODERN CUPOLAS. 1 45 

SO that there is very little dead space, the blast reaching every 
part where it is wanted, being distributed evenly. Therefore, 
the lining is not affected by the action of the blast to the ex- 
tent that would be expected where upper and lower tuyeres 
are used and two zones of melting are at work. There are six 
lower and six upper tuyeres which tend downward. This 
makes better combustion and prevents molten iron from enter- 
ing the wind chamber through the tuyeres. Through the 
greater portion of the heat there is very little or no flame 
shown at charging doors, showing that the upper tuyeres pro- 
vide sufficient oxygen where it is wanted below the stock in 
the cupola where the heat is most severe. 

The tuyeres are rendered readily adjustable by a novel and 
simple arrangement. The tuyere boxes are made double or in 
two sections when desired, and when it is deemed advisable to 
lower the tuyeres, bricks are removed from the lower section 
and placed in the upper one. In this way the tuyeres may be 
raised or lowered in a few minutes without disturbing the lining 
outside of the tuyeres. 

A low safety tuyere and trap with soft metal plug is pro- 
vided, which discharges any overflow through the bottom 
plate. Therefore should the iron rise unexpectedly there is no 
possibility of it getting into the wind chamber through the 
tuyeres and injuring the chamber, as the cornucopia-shaped 
trap shown in Fig. 32 receives it and permits it to flow at once 
out of the chamber. 

The upper tuyeres can be opened or closed by the turn of a 
crank that is arranged for opening and closing them, and the 
cupola made a single tuyere cupola for small heats or a double 
tuyere one for a large one when fast melting is required. 

A slag-hole spout is placed in the back so the slag can be 
drawn off at will. It is this fact that makes this cupola a con- 
tinuous melter. 

The cupola is made of any size wanted, from 12-inch inside 
diameter up to any capacity desired, and is constructed in three 
sections or distinct parts, viz.: No. i, bottom plate and sup- 
10 



146 



THE CUPOLA FURNACE. 



ports; No. 2, portion of base 3 to 5 feet high, according to 
size of cupola, with air chamber, upper and lower tuyeres, tap 
trough, slag spout and blast gauge; No. 3, casing, charging 



Fig. 31. 




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SECTION OF PAXSON COLLIAU Cl'POLA. 



MODERN CUPOLAS. 



147 



doors and stack. The cupola may be ordered complete or in 
parts, thus enabling parties desiring to make only a small outlay 
to obtain a fully up-to-date cupola by ordering only the essential 
parts of it and constructing the remainder from material at hand. 
The legs or supports are made any length desired from 2 to 
7 feet, so that the cupola may be placed at a height suitable for 
ladles used in pouring or that a car may be placed under 
cupola for receiving the dump and removing it to the yard or 
tumbling barrels, where it may be quickly cooled and milled. 



Fig. 




The drop doors, when desired, are fitted with counter-balance 
weights to facilitate raising them into place. 

In Fig. 33 is seen the indestructible wire screen charging 
door with which this cupola is fitted. It requires no lining and 
does not warp or crack. As before stated in this work, a 
charging door has nothing to do with a cupola melting, and is 
only of use to give draught for lighting up and prevent sparks 
or pieces of fuel being thrown upon the scaffold toward the 
latter end of a heat, and this door answers every purpose. It 



148 THE CUPOLA FURNACE. 

is hung on the outside of the cupola and does not come in con- 
tact with the heat to the same extent as the lined or iron door, 
is lighter and easy to swing and lasts longer than either of the 
others. This door, although called indestructible, does not 
last forever, and its frame is constructed in such a way that the 
wire screen when destroyed by slow corrosion may be re- 
moved and replaced with a new one in a very short time. 

Small cupolas of this construction are made especially for 
the use of technical schools and colleges, and also for use in 
large foundries for testing brands of pig iron, and in interior 
towns for melting small quantities of iron. 

THE WHITING CUPOLA. 

In Fig. 34 is seen the Whiting patented cupola, designed by 
Mr. Whiting, a practical foundryman, of which the following 
description is given by him: 

The universal satisfaction given by the Whiting cupola is 
largely due to the patented arrangement and construction of 
the tuyere system, which^is so designed as to distribute the 
blast most efficiently, carrying it to those portions of the cupola 
where it will do the most good, under a reduced pressure, and 
through an increased area. 

There are two rows of tuyeres. The lower ones are arranged 
to form an annular air inlet, distributing the blast continuously 
around the entire circumference of the cupola. 

This system of tuyeres is also arranged to be adjusted ver- 
tically. This provides for adjustment to the class of work, 
kind of fuel, and changes in the inside diameter of the cupola. 
These tuyeres are flaring in shape and admit the blast through 
a small area which is expanded into a large horizontal opening 
on the inside of the cupola, thus permitting the air to reach the 
fuel through an area nearly double that through which it enters 
the tuyeres — admitting the same volume of blast, but softening 
its force. 

There is an upper row of tuyeres of similar construction to 
supply sufficient air to utilize to the fullest extent the escaping 



MODERN CUPOLAS. 



149 



carbon gas. These tuyeres are of great service in melting and 
in large heats — for small heats they may be closed by means 
of our improved tuyere dampers. 

Fig. 34 represents the latest type of the Whiting patent 
cupola. A half-vertical section is represented, showing the 
arrangement of the improved tuyeres and the method of ad- 

FiG. 34. 




ELEVATION. 



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'Wl 



m- 



SECTION 



SECTION OF WHITING CUPOLA. 



justing them vertically. These tuyeres are arranged on slides 
and can be placed at various heights, as shown by dotted lines. 
It sometimes happens that the operator finds the cupola too 
large for his needs. When this is the case, a thicker lining can 
be used and the tuyeres adjusted accordingly, and for small 



150 THE CUPOLA FURNACE. 

heats the proper ratio of coke to iron can be maintained ; other- 
wise a large cupola running small heats will decrease this ratio 
materiall)', adding considerably to the cost of castings. 

A change can be made from coke to coal fuel and the bed 
made of suitable depth, by simply adjusting these tuyeres. 

No other cupola has this device. It practically gives the 
operator two cupolas in one. 

This figure also shows the safety alarm attachment, side 
plates, improved blast meter and upper tuyere dampers, etc. 

Every cupola is provided with the foregoing improvements,^ 
together with foundation plate, bottom plate and doors, columns 
(three to five feet long), slag and tapping spouts and frames, 
peep holes with fittings, patent tuyeres and charging doors 
and frames. All fitted ready to erect. 

THE EJE CUPOLA. 

The illustration, Fig. 35, shows the general external appear- 
ance of the standard EJE Cupola, the above cut showing Body 
Section X. The blast pipe entering the wind box on a tangent 
has been found to be the most successful method for the en- 
trance of the blast, and the heavy construction of castings 
forming hearth plate, drop doors and legs will be noted. 

Tuyere System. — The EJE Cupola is furnished with two rows 
of tuyeres as shown in the illustration, the upper row being so 
spaced that they come exactly halfway between the tuyeres on 
the lower row, distributing the air evenly throughout the bed 
of the cupola. The tuyeres are flaring in shape; the air enters 
through a small opening in the shell, same expanding into a 
larger one in the inner circle of the cupola, finally reaching the 
fuel through an opening of almost double the area of the one 
through which it enters the tuyeres, thereby reducing the air 
pressure while admitting the same volume, thus softening the 
blast. 

Note the space between the openings of the lower tuyeres on 
inside of cupola is reduced to the minimum, allowing air to 
enter the cupola from almost every point on the inner cir- 
cumference. 



MODERN CUPOLAS. 



151 



The upper tuyeres are of similar construction to the lower 
and supply sufficient air to consume all escaping fuel gas; they 
are of great service during long heats or, if very quick melting 
is desired, they may be opened or closed independently of each 
other by a small damper operated from outside of the cupola. 

POINTS OF SPECIAL MERIT IN THE EJE CUPOLA. 

Two or more Safety Tuyeres are provided with each cupola, 

Fig. 35. 




E. J. E. CUPOLA-BODY SECTION. 



which give automatic warning when the operator allows iron to 
get too high in the cupola. A cast-iron box flared at top directly 
under each Safety Tuyere positively prevents any overflow of 
metal getting into the Wind Box. 



152 THE CUPOLA FURNACE. 

Tapping Spout cast iron, of improved design, of extra width 
and depth. 

Slag Spout is of heavy cast iron, of sufficient length to allow 
slag to run into small wagons, if so desired. 

Cleaniug Doors are of cast iron, very readily removed, allow- 
ing furnace tender to easily clean out interior of air chamber 
when necessary. Two cleaning doors on sizes up to and in- 
cluding No. 66, and four on all sizes above. 

Peep Hole Frames and hinged covers machined air-tight are 
placed opposite all tuyeres, upper and lower, covers are fitted 
with mica peep holes and can be opened when necessary to 
get into tuyeres. 

A Mercury Blast Gauge of improved design is furnished with 
each cupola; the gauge is enclosed in an iron box with hinged 
cover, keeping the glass clean and preventing breakage. 

Tuyere System — The tuyeres are of such a shape that they will 
readily hold themselves in the lining and will distribute the air 
equally throughout the melting zone. The upper tuyeres can 
be opened or closed by means of a small damper. 

Linhig Supports of cast iron are bolted to the inside of the 
stack and are of sufficient strength to support the lining; one 
shelf is placed above the melting zone, one above the charging 
doors and others in the stack, the number, of course, depend- 
ing upon the height of stack desired. 

In Fig. 36 may be seen the inside construction and general 
design of the Calumet Cupola. 

As an iron melter this cupola, being the latest design, pos- 
sesses all modern features of economy of fuel and lining, rapid 
and continuous melting, resulting in a hot fluid iron of uniform 
grade throughout the heat, and a wide range of work. 

The design is the simplest and strongest yet produced in a 
cupola, and the construction is of the highest grade both as to 
material and workmanship. 

While all essential features of previous designs are retained, 
new features of importance are to be found exclusively on this 
cupola. 



MODERN CUPOLAS. 



153 



Air Chambers. — A conspicuous feature of the design of a 
Calumet Cupola is the placing of the air chamber inside the 

Fig. 36. 




CALUMET CUPOLA. 



furnace shell. This construction increases the thickness of the 
lining at the melting zone just above the tuyeres, thus avoiding 



154 'I'HE CUPOLA FURNACE. 

any burning of the shell due to destruction of the lining at this 
point. By thus placing the shell on the outside it is easily in- 
spected at the bottom where inaccessible cupola shells usually 
fail because of rust. The inside plate of the air chamber being 
removable may be replaced if burned out. The conical shape 
of the furnace shell results in an enlarged base, giving great 
stiffness and stability to the cupola. These features of the de- 
sign will be readily appreciated, as they greatly increase the 
strength and life of the cupola. 

Blast Inlets, one on each side, to insure equal distribution of 
blast around cupola, may be attached as location of cupola re- 
quires, and may be either radial or tangential. 

Tuyeres are of the modern rectangular, expanded type, prop- 
erly proportioned to the cupola area and the outlet of any 
standard blower, and provide a nearly continuous blast open- 
ing around the furnace walls. The upper tuyeres provide an 
air supply to complete the combustion, and are equipped with 
dampers for closing them if desired. A safety tuyere is pro- 
vided near the slag spout, which prevents the molten iron rising 
and flowing through the lower tuyeres. 

Shell and Stack are of steel plate riveted in sections with 
downward joints, convenient for erection. Angle lining sup- 
ports are riveted to the shell at intervals, and the lining is of 
standard fire brick. 

Furnace Supports. — The cupola rests upon a heavy cast-iron 
flanged base ring, to which the furnace shell is bolted on the 
outside, and the removable air chamber plate on the inside. 
The cast ring rests upon ribbed columns which stand upon cast 
base plates, held together with steel rods. The base plates 
amply distribute the weight. The columns are curved to allow 
the drop doors to swing back free of the dump. 

Doors and Peep Holes — The drop doors are hinged to the 
base ring by heavy lugs and pins. They are substantially 
ribbed, are perforated, and provided with eyes for inserting a 
lifting rod. 

The charging door mgy be of the perforated plate or screen 



MODERN CUPOLAS. I 55 

type, or it may be of cast-iron arranged for brick lining, the 
latter being the standard construction. 

Clean-out doors are provided in the air chamber, being 
machine fitted in an air-tight manner. 

Peep holes are provided opposite each tuyere, being of 
mica mounted in removable frames, which are machine fitted 
to be air-tight. 

Spouts — The spouts enter the furnace through cast-iron 
frames in the air chamber, bolted to the shell. 

The slag spout is adjustable to suit the height of the tuyeres. 

The tap spout is located opposite the slag spout, and may 
be of any length required. 



CHAPTER Vll. 

LARGE CUPOLAS. 
THE HOMESTEAD LARGE CUPOLAS. 

Probably the largest cupolas in this country are those of the 
Carnegie Steel Works, Homestead, Pa. These cupolas, four in 
number, were constructed for the purpose of melting pig iron 
for converting into steel by the Bessemer process, and are of 
the following dimensions : 

Diameter of cupola casing, 12 feet. 

Diameter of cupola stack, 12 feet. 

Height of charging opening above iron bottom, 30 feet. 

Height of stack, 15 feet. 

Stack supported on cast-iron columns 3 feet long, resting on 
top of cupola casing, with opening all around for charging 
stock from blast furnace barrows. 

Thickness of lining to a short distance above tuyeres, 27 
inches. 

Thickness of lining from this point to top of cupola, 12 
inches. 

Diameter of cupola at tuyeres, 7^ feet. 

Diameter of cupola above tuyeres, 10 feet. 

Diameter of stack, 12 feet. 

So little heat escaped from top of cupola it was not found 
mecessary to line the stack. 

Number of tuyeres, 16. 

Size of tuyeres, 4x6 inches. 

Height of tuyeres above iron bottom, 6 feet. 

The tuyeres were placed at so great a height for the purpose 
of holding molten iron in the cupola for a charge of a Bessemer 
converter. 

(156) 



LARGE CUPOLAS. I 57 

These cupolas were designed to be kept in blast as long as 
the lining would last, and for this reason the casing from the 
bottom plate to above the melting zone was constructed of cast 
iron flanged sections, bolted together on the outside, so that in 
case the casing burned through a section could be removed 
and replaced by a new one. But this method was not found 
to be practical and the cupolas were only kept in blast from i 
a. m. Monday morning until Saturday noon before dumping. 

These cupolas which have probably been abondoned since 
the construction of a bridge across the Monongahela River for 
conveying molten iron direct from the blast furnace to the con- 
verters, were never a success so far as making hot iron or rapid 
melting was concerned for they seldom produced hot fluid iron 
and the melting capacity of each one did not exceed 12 tons 
per hour, while the melting area at the melting zone was suf- 
ficient to have melted 30 tons per hour. This was no doubt 
due to the diameter at the tuyeres being too great for forcing 
blast to the center of the stock from side tuyeres, and the 
cupola not melting properly in the center. The Jumbo cupola 
described elsewhere in this work which is only 54 inches 
diameter at the tuyeres melted 15 tons per hour of hot fluid iron 
for stove plates, soil pipes, etc. 

Had these cupolas been contracted at the tuyeres, to some- 
where near this diameter, and the lining shaped upon a plan 
similar to that of the construction of the Jumbo Cupola, their 
melting capacity per hour would no doubt have been double, 
and a great deal less fuel required in melting. 

In all cases, the lining of very large cupolas should be shaped 
similar to that of a blast furnace, for it is only by getting the 
blast to the center of the stock in these furnaces that they are 
made to produce the enormous quantities of iron they are 
capable of producing. This is done by contracting or boshing 
the furnace near the bottom, where the blast enters the stock, 

THE McSHANE LARGE CUPOLA. 

Another very large cupola that attracted considerable atten- 



158 THE CUPOLA FURNACE. 

tion at the time of its construction was one at the McShane 
foundry plant, Baltimore, Md. This cupola was 98 inches in 
diameter inside the lining, and was designed to melt iron for 
soil pipe, plumbers' fittings, etc., such castings requiring very- 
fluid hot iron to run them. It, however, was not a success as 
regards making iron hot or rapid melting with the above 
diameter. 

This was attributed to the force or volume of blast not being 
sufificient for the size of the cupola. But a larger blower when 
placed in operation produced but little better results. Failure 
was then attributed to the tuyeres, but numerous changes in 
their size and design gave no better results, and it was not until 
the diameter of the cupola was greatly reduced by increased 
thickness of lining that a satisfactory iron was melted, with a 
melting capacity per hour greatly reduced from that originally 
designed or calculated. This cupola, which is still in use, was 
declared a Jonah soon after its construction. It melts very 
unevenly, producing hot, even iron for a while and then dull, 
uneven iron. 

When called upon a few years ago to locate the cause of this 
uneven melting, I found that the twenty inches or more of lin- 
ing put in to reduce the diameter had become shaky, and a great 
deal of the blast escaped through the lining instead of passing 
through the stock, and heat escaping through the melting zone 
was not all utilized in heating and preparing the iron for melt- 
ing before descending into the melting zone. This is a diffi- 
culty that may be remedied by using a good plastic, adhesive 
material in laying up the lining and by carefully daubing any 
openings that may occur in it all the way up to the charging 
door. 

But these are precautions seldom taken by cupola men unless 
their attention is frequently called to them, and it is far better 
and more economical to have a cupola constructed of the de- 
sired size with the proper thickness of lining than to reduce the 
diameter by extra thickness of lining. Another trouble with 
this cupola was the colored help employed to man it. These 



LARGE CUPOLAS. I 59 

men frequently permitted the stock to get too low in the cupola 
for good melting, and when it became very hot at the charging 
door, stood back, and blast had occasionally to be taken ofif 
until the cupola was filled up. This was very bad cupola 
practice. 

THE THOS. D. WEST LARGE CUPOLA. 

To overcome the difificulty in cupolas of large diameter, not 
melting well at the center of the stock, Thos. D. West con- 
structed at the plant of the Thos, D. West Foundry Co., 
Sharpsville. Pa., a cupola, having a 92-inch shell, lined with 
8-inch brick, giving a diameter of 76-inch inside the lining. In 
this cupola, in addition to the usual number of side tuyeres 
placed in cupolas of this size, he placed a center blast tuyere, 
the top of which stood three feet above the iron bottom. It 
was constructed of heavy cast-iron pipe upon which prickers 
were cast for holding daubing. It extended up from the floor 
and was made permanent or stationary in the cupola, the bottom 
doors being cut out to fit up around it. On the top of this 
pipe was placed a hood or rounded cover fifteen inches in 
diameter, from under which the blast entered the stock all 
around the hood. The pipe and hood were daubed for each 
heat with the same daubing material used for repairing the cupola 
lining, and the sand bottom was made up around the pipe. 
This cupola melted, when in blast and properly charged, from 
eighteen to twenty tons per hour, and was pronounced a suc- 
cess by Mr. West. However, there was at times more or less 
trouble with the center blast, due to the daubing being knocked 
or rubbed off the hood by the stock when thrown in and iron 
getting into the tuyere, and also from the tuyere pipe being 
crowded to one side by an uneven settling of the stock and 
causing a leak through the sand bottom. 

The foreman at the plant, when visited by the writer a few 
weeks ago was of the opinion that these difficulties could have 
been overcome by covering the hood with fire brick, in place of 
daubing, and constructing the tuyere pipe in a more substantial 
manner. This firm is engaged in the casting of ingot moulds 



l60 THE CUPOLA FURNACE. 

by the direct process, and this cupola is designed only for 
melting iron when the blast furnace, from which they obtained 
their molten supply was not making iron suitable for their cast- 
ings. But since its construction, the firm have arranged to ab- 
tain molten iron from any one of three blast furnaces that ma}'' 
be producing suitable material for their castings, and the 
cupola has not been in blast for the last three years, and is not 
likely to be put in blast again, so that these points may never 
be determined. However, the principle is no doubt correct 
and, if the difficulties that have been met with in the use of a 
center blast tuyere can be overcome by making this tuyere 
stationary and more substantial, large cupolas can be made to 
melt as well at the center as smaller ones by the use of this, 
tuyere in addition to outside tuyeres. Another plan of making 
large cupolas melt at the center, is to contract them at the 
tuyeres to a diameter of 55 to 60 inches. This diameter has 
been shown by numerous tests to be about the proper one at 
the tuyeres for fast and economical melting. 

Straight cupolas of larger diameters than this, have been 
made to do fast melting by the use of large positive blast 
blowers; but this has been done with considerable uncertainty 
as to a hot even temperature of iron throughout the heat, and 
at a greater expense for power, than actually necessary for the 
amount of iron melted per hour or during a heat. A diameter 
of 55 to 60 in. at the tuyeres may readily be obtained in 
cupolas of larger size without danger of bridging or hanging 
up, by boshing the cupola, as shown in Figs. 68, 'j'j and 79,. 
from the bottom plate to a short distance above the tuyeres, or 
contracting it at the tuyeres only as shown in Figs. 65 and 66y 
or by placing the Zippier or Knoeppell tuyeres in the cupola. 

Each of these plans has given hot even iron with less fuel in 
large cupolas than could be obtained in cupolas of over 60 
inches in diameter at the tuyeres. The boshing from the bot- 
tom plate up, is by far the best plan for cupolas from which 
iron is drawn as fast as melted, as considerable less coke is re- 
quired for a bed. The molten iron is more concentrated in its. 



LARGE CUPOLLS. l6l 

descent and reaches the tap hole more rapidly and hotter iron 
may be obtained. But when it is necessary to hold molten 
iron in a cupola while waiting for a large ladle to be returned 
from the casting floor, or iron is held upon the erroneous theory 
that when molten it may be kept hotter in a cupola than in a 
ladle, the tuyeres have to be placed higher up, and this saving 
in coke in the bed is not cfTected ; for this style of melting, the 
projecting tuyere will probably give the best results. 

Each of these shaped linings and arrangement of tuyeres has 
given excellent results in melting in large cupolas, but these 
results can only be obtained by kee[Mng the lining in the shape 
outlined in the illustrations. To maintain this shape, a blue 
print of the design adopted should be framed and hung up 
near the cupola for the guidance of the mclter and foreman, in 
case the cupola does not coniinue to give the melting results 
obtained in the first or trial heats. The success of all fancy 
shaped linings depends upon maintaining the shapes that give 
the best results in melting. 

ADVANTAGES AND DISADVANTAGES OF LARGE CUPOLAS. 

The advantages claimed for a large cupola capable of melt- 
ing all the iron lequired for a plant in the shortest possible 
time are, that it admits of iron, fuel, and all cupola material be- 
ing concentrated in one point, in the yard or stock room. 

One blower is all that is required. 

One elevator or other device for getting up iron or fuel is 
sufficient. 

Less lining and daubing material is required. 

Only one melter is required and fewer men are necessary to 
man one cupola than two. 

All these claims are correct up to a certain point, but beyond 
this point they almost entirely disappear. For a large blower 
frequently costs more than two smaller ones, and more power 
is required to run it than two small ones. With onl)' one ele- 
vator or other device provided for getting up stock, men fre- 
quently have to wait their turns to use it, and in many cases 
II 



1 62 THE CUPOLA FURNACE. 

for this reason more men are required for getting up stock for 
one cupola than for two smaller ones, melting the same num- 
ber of tons. 

In cupolas melting from eighteen to twenty tons per hour, 
the stock settles so rapidly that extra men are required in 
charging, to keep the cupola filled to the charging door, and if 
it gets awa}' from them it becomes so hot that blast has to be 
taken oiT until filled up. 

Fuel and iron have to be thrown in so rapidly that the fuel 
is often not evenly distributed or the different brands of iron 
are not properly mixed in charging, the result being an iron of 
uneven temperature at the spout, and also an uneven grade of 
iron from the mixture. For heavy work, or water pipe, car 
wheels, etc., this may not be an objectionable feature, for the 
iron is handled in large ladles and the temperature may be 
equalized in the ladle and the iron mixed, and an even grade 
obtained from the mixture. But for light work such iron is 
unfit for objects to be cast, and it is only when it is handled in 
large ladles by crane or tracks that it can be used and an even 
grade of it in the castings obtained. 

Another objection to the very large cupola for light work is 
the long distance the molten iron has to be carried when this 
is done by crane or track, the iron frequently becoming too 
dull to run the work, and many castings are lost. When car- 
ried by hand the iron not only becomes dull, but more time is 
required for casting and hence less time for molding. It will 
thus readily be seen that while there are advantages in concen- 
trating all the melting at one point in one cupola, there are also 
many important disadvantages. As a rule it is more profitable 
to install two or more cupolas than one large one, and these 
should be placed at the most convenient point for distributing 
in the shortest possible length of time molten iron to the work 
to be cast. For more time can be taken in bringing cold iron 
to a cupola than in getting molten iron away from it. What is 
meant by a large cupola is one capable of melting 1 8 to 20 or 
more tons per hour. When this amount of iron is required it 



LARGE CUPOLAS. 1 63 

will generally be found more profitable to install two cupolas 
to melt it than one, especially for light work, and to place them 
at such a distance apart as will give the shortest possible carry 
for the molten iron. By this arrangement hotter and more 
fluid iron can be delivered at the moulds with a minimum 
amount of labor and time, and even for the heavier class of 
work this will be found to be of advantage in making sound, 
clean castings. Another matter that must be considered before 
installing a large cupola is the method of handling the molten 
iron with large ladles. Almost any amount can be handled per 
hour if sufificient ladles and means of handling them are pro- 
vided, but with small hand and bull ladles the amount of iron 
that can be taken from a cupola spout running a continuous 
stream is only about 8 ton per hour. Even this amount re- 
quires very rapid handling of ladles, and if the stream once gets 
away from the men and it becomes necessary to stop in to re- 
move iron from the floor and get control of the stream, even 
faster handling is necessary to get rid of the iron accumulated 
in the cupola during the stop-in, and the danger of handling 
the iron is increased. 

For this reason two tap holes should always be placed in a 
cupola melting over 8 tons per hour when the iron is all han- 
dled in small ladles. 



CHAPTER VIII. 

SMALL CUPOLAS. 

In the early days of foundry practice in this country only 
small cupolas were used. A fifteen to tv\enty inch inside 
diameter cupola was considered to be the proper size for a 
jobbing foundry, and a diameter of forty inches was the limit 
for large cupolas. In foundries equipped for heavy castings 
three cupolas of dififerent sizes were installed and arranged to 
be put in blast separately, or all placed in blast at the same 
time. When a piece was to be cast requiring more iron than 
could be melted in the largest cupola in a given time, one or 
more additional cupolas were put in blast at the same time, 
and in this way the founder was able to cast the largest piece 
required in those days. This arrangement also saved consider- 
able fuel, for the founder could put in blast a cupola to suit the 
size of his heat and adapt himself to good or bad times, a thing 
that cannot be done at the present time in cupola practice in 
many foundries. 

With the increase in the size and capacity of foundries the 
size of cupolas were also increased until we now have them up 
to ten feet inside diameter, and one would think from reading 
cupola literature in scientific papers and monthly periodicals, 
most all of which matter pertains to practice in large cupolas, 
that the small cupola had gone out of use. This is by no 
means the case, for the small cupola has kept pace with the 
large one in improvement of design and construction, and is 
still extensively used, not only in the small foundries where its 
capacity fills the requirement of the foundry for work to be 
cast, but also in large foundries in many of which its value as 
a money maker or saver has been overlooked by the manage- 

(164)- 



SMALL CUPOLAS. 1 65 

ment. It is well known among practical founders that neither 
fracture indication nor chemical analysis accurately indicates 
the resultant quality of an iron that may be obtained from a 
new or untried brand when added to or used to replace another 
brand of iron in the regular foundry mixtures. To determine- 
this accuratcl}- the iron must be actually melted and cast, and 
may result in the loss of an entire heat or part of a heat from 
the iron being too hard, soft or weak for the work to be cast. 
Such loss may be reduced to a minimum by first testing a new 
brand or mixture of iron in a small cupola capable of melting 
from a two hundred weight to a ton, and casting all or part of 
it into the regular line of castings and the balance into unim- 
portant castings. It is absolutely necessary that in all tests of 
this kind a siifificient quantity should be melted to insure a hot 
fluid iron to run the work and the mixing of the different 
brands in the mixture, which cannot be done with only a few 
pounds of each brand. The small cupola is of value in making 
a mixture for a few hard or strong castings such as gearwheels 
or chilled castings when the regular heat is all soft iron, or a 
few soft castings when tiie heat is hard iron. This is done by 
melting the hard or strong iron in the small cupola at the same 
time the regular heat is being melted, and mixing the two 
molten irons in a ladle. 

In this way after a little practice an iron of any degree of 
hardness may be obtained without risk of hard iron getting 
into soft work, as would be the case if a special charge of hard 
iron were made in the regular heat. In the same way a few 
softer castings may be cast when the regular heat is hard iron, 
by melting a high silicon iron in the small cupola and mixing 
it with the hard iron. 

This practice is now regularly followed in many large foun- 
dries making only a limited number of castings for which a 
hard, close, strong iron is required. A semi-steel mixture may 
also be made in this way more accurately than when the mix- 
ture of iron and steel is melted together in the cupola. The 
small cupola is also of value in a large stove foundry for cast- 



1 66 THE CUPOLA FURNACE. 

ing patterns or getting out a few repairs when the foundry is 
shut down. And in the large machine or jobbing foundry for 
turning out a few castings when shut down or getting out a rush 
order for a breakdown, furnishing hot iron for feeding up a 
.large casting after the heat has been melted and bottom 
dropped, etc. 

SWIVEL CUPOLAS. 

Now in Fig. 37 is shown a small cupola known as the Swivel 
Cupola, from being hung upon bearings in the center upon 
which it may be turned upside down to dump after a heat, or 
laid upon its side in chipping out and in repairing the lining. 
This style of small cupola is an old one, and was described in 
the writer's first work on cupola practice published in 1877. It 
was first made with a stationary bottom, and designed to be 
dumped after a heat by turning it upside down, but this was 
found to be impracticable, for the bottom became heavy and 
hot at the end of a heat and difficult to turn, and when turned 
only a limited amount of the melting refuse dropped out. 
The dropped bottom was therefore added and the cupola laid 
on its side for chipping out and repairing the lining. This de- 
sign is best suited for cupolas of from twelve to fourteen inches 
diameter, for if made of larger diameter it is too heavy to turn. 
The top of the cupola must have room for turning under the 
stack plate, and does not connect with the stack by several 
inches. It should therefore be of sufficient length to hold the 
required amount of stock, as none of it can be placed in the 
stack in charging. Cupolas of this design melt well when 
properly constructed and managed, and are nfiOre convenient 
for chipping out and repairing the lining than any other design 
of very small cupolas. This cupola calls to mind a small one 
in use at the foundry of Charles Spangler, of Allentown, Pa., 
which was probably originally designed for a swivel cupola. 
The stack is supported upon iron columns, as shown in Fig. 37, 
but the smaller section is mounted upon four small wheels 
placed at the bottom upon iron rails upon which this section is 



SMALL CUPOLAS. 
Fig. 37. 



167 




I 68 THE CUPOLA FURNACE. 

drawn from under the stack for chipping out and daubing. 
This section is only about four feet long, and can readily be 
chipped out with a bar from the top and the lining repaired at 
the melting zone without going into the cupola. When the 
lining has been repaired it is put back in place and the joint 
between the cupola and stack is luted. This luting makes the 
connection between the stack and cupola and admits of the 
charging door being placed at any desired height, it being for 
this reason a more desirable design for the larger-sized small 
cupola than the swivel cupola. This cupola has been in con- 
stant use for many years, and supplies from two to six moulders 
with iron for light castings. 

A PORTABLE SMALL CUPOLA. 

The illustration Fig. 38 recently appeared in" The Foundry" 
together with the following description by Mr. Dan Calvin, 

All foundries have to produce castings in a hurry at times, 
and sometimes it is inconvenient to wait for iron from the regu- 
lar cupola or to fire up one of the large cupolas for a small 
quantity of metal. A small portable cupola such as that shown 
in the accompanying illustration, will be found very serviceable 
indeed for such occasions as this. The cupola shown is in use 
in Paducah, Ky. It has no stack and is set against one wall of 
the foundry. Air for the blast comes from the blacksmith 
shop, which is about 20 feet away, the air being conducted 
through a pi{)e underground and brought up behind the cupola 
as shown. Connection is made with the cupola by means of a 
gland, as shown in the illustration. The diameter of the shell 
is 18 inches and the height of the shell 5 feet. All of the cast- 
ings for the cupola were made in open sand, and the construc- 
tion was such that very little patternmaking was required. 

The bussel pipe is a ring of square cross section, about 5 
inches on a side. The tuyeres are made from i}4 inch pipe. 
The cupola is mounted upon a frame upon wheels, as shown, 
so that it can be moved away from the wall for cleaning and 
repairs. The A-shaped frame which supports the trunnion is 



SMALL CUFOLAS. 



169 



5 feet high, tlie center of the trunnion about 3 feet 6 inches 
irom the floor. 

When in use the cupola is Hned with molding sand, % of an 
inch thick. A casting weighing 300 pounds can be made with 
this cupola, and a heat of 700 pounds of metal can be taken 
from it. The charges for such a heat are as follows: Three 



Fir. 38. 




riddlesfull of coke for the bed and 300 pounds of iron. This is 
followed by two charges composed of one riddle full of coke 
and 150 pounds of iron each, and one charge of one riddleful 
of coke and 100 pounds of iron. 

The cupola can be gotten ready and hot iron available in 
from an hour to an hour and a half at any time. When large 



170 THE CUPOLA FURNACE. 

brass castings are required, the cupola is simply relined and 
from 300 to 400 pounds of brass melted in it without any 
difficulty.* 

A CHEAP SMALL MOVABLE CUPOLA. 

In many foundries the cupola arrangement is such that the 
addition of a small cupola near the scaffold and blast pipe 
would be in the way and a movable cupola is therefore desired. 
A small neat and practical cheap construction answering this 
purpose has been in use for many years in a foundry at Tren- 
ton, N. J. This cupola is constructed in two sections each of 
which is about four feet long. To the lower section are at- 
tached the bottom plate, cupola legs or supports and drop 
door. Each section is provided with lugs or handles near the 
top for lifting. When wanted for melting, the lower section is 
lifted with the crane and placed in position alongside of the 
cupola scaffold, and the other section is placed on top of it, 
and the joint luted with clay. Connection is made with the 
cupola blast pipe and the cupola is ready for use. The foundry 
roof being high, no stack is required and the cupola is charged 
at the top from the regular cupola scaffold, making this prob- 
ably the cheapest small movable cupola that can be designed. 
After a heat has been melted, if the cupola is no longer wanted 
for immediate use, the sections may be lifted with the crane 
and placed in a corner out of the way until again wanted. This 
cupola has been put in blast daily for months to melt iron for 
two moidders casting wagon boxes, and cheaper melting was 
done than could have been effected in the regular foundry 
cupolas for this number of moulders on light work. Many 
other cheap small cupolas that the writer has seen in operation 
in foundries might be described such as an old steam boiler, or 

* This cupola when lined as described would have a diameter of sixteen and a 
half inches and the tuyere area is entirely too small for a cupola of this size. The 
lining of three fourths of an inch of moulding sand is too light for a l')ng heat and 
the lining material is loo friable for safety, as it may readily be knocked or rubbed 
off in charging ard setting of the stuck. At least a two inch firebrick lining should 
be placed m all small cupolas, and if long heats are to be melted a four-inch lining 
will prove more satisfactory. 



SMALL CUPOLAS, 171 

smoke stack set on end and lined, or two or three wooden 
barrels placed one on top of the other and lined. In fact, small 
cupolas have been made by small foundries in their efforts to 
get into business, from almost every old cast-ofF material hav- 
ing the shape of a cupola that would hold a lining in place, and 
iron has been successfully melted in them for years, or until the 
founder could afford to construct or purchase a better cupola. 
The small cupola is more difficult to manage than a large 
one as the tendency to bridge or bung up is greater, but a 
twelve-inch cupola may be kept in blast for ten hours or more 
and good melting done if properly charged and fluxed. In 
England cupolas of this diameter have been kept in blast for a 
week without repairs to lining by knocking out the front after 
a heat, raking out the slag and refuse, putting in a new front 
and bed of coke to be ready for charging iron the next morn- 
ing. In this way the melter was able to put the blast on at 
seven in the morning and melt all day. 

THE KEEP SECTIONAL CUPOLA. 

In Fig. 39 is shown the Keep Sectional Cupola designed by 
Mr. W. J. Keep, the well-known authority on foundry practice, 
and inventor of mechanical analysis. 

It is made in sections, 18 inches deep and about 27 inches 
outside diameter (Fig. 40). These are lined with ordinary 
stock brick laid flatwise. The complete lining is about three 
inches thick, making the inside diameter 21 to 22 inches. A 
ring of angle iron is riveted to both ends of each section for 
stiffness, to hold the brick in place and to make a joint between 
sections. The lower section contains a wind box and tuyeres. 
This section is set on a solid truck on wheels, so that the cupola 
can be rolled to any point required. The wheels can be either 
flanged for a track, or flat tread wheels. The sections can be 
handled either by a trolley, placed a little to one side of the 
stack, and with an ordinary chain hoist, or by a light bracket 
or jib crane. 

The stack may be suspended by rods or otherwise from the 
foundry roof. It is 27 inches in diameter, and flares at the 



\J2 



THE CUPOLA FURNACE. 



lower end, which is about eight feet from the floor, and is just 
high enough for the cupola to roll under it. One side of the 
flaring portion is cut away for a charging door. The three 
inch opening between the top of the cupola and the edge of 
the stack creates a strong draft and keeps the air fresh around 
the cupola. 

To take off a heat the bed-plate is rolled under the trolley 
track, and the lower section put in place. The sand bottom is 
put in, 2^ inches thick at the front and 3 J^ inches at the back. 
The spout is lined, the breast put in, and a slag hole made at 
the rear. Shavings and kindling are laid in this section and 
the other three sections put in place, daubing the joints on the 
inside. 

¥\c,. T,(). Fig, 40. 





The cupola is then rolled under the stack, and the pipe be- 
tween the blower and the wind box connected. A charging 
platform should be made of boxes or flasks and coke charged. 
The fire is usually lighted two hours before charging iron. 
When the coke is well lighted iron and coke should be charged 
in accordance with directions furnished by the manufacturers. 
The cupola holds three charges, which can be placed in 15 to 
20 minutes. 

The pig iron is to be broken into pieces about 10 inches 
long, and the scrap as small, and charged evenly. The blast is 
put on 15 minute; before iron. 



SMALL CUPOLAS. 



173 



The cupola will melt about 2,000 pounds of iron per hour, 
and eighteen charges, or 3,600 pounds can be melted at one 
heat. Two or three heats may be made the same day. The 
blast can be delivered from a small fan driven by belt or motor. 

The following are some of the advantages claimed for this 
cupola: A test chaige of ico pounds of iron will show the 
quality of any pig iron or mixture if the fire has burned two 
hours, that is, if the cupola is as hot as the average large 
cupola. On days when, from any cause, the large cupolas are 
not run, the foreman and his assistants can mold and take off 
two or three heats, and earn part if not the whole of their 
wages; and at the same time do work that is needed. Duiing 
any shutdown, repair castings can be made for quick " while 
you. wait " repairs. The iron may be ready to pour by the 
time a piece is molded. If an important piece is lost at the 
regular heat, it can be made the same night or early next 
morning. For special mixtures, such as white iron, chilling 
iion, semi-steel or soft iron for patterns, the results will always 
be as calculated. If molders break a heat, the cupola can be 
rolled in place and started before the men get out of the shop, 
and work that is needed can be made, so as to keep the rest of 
the shop running. As a result, very few heats are brtjken. 
For portable use by miners, contractors and technical schools, 
it recommends itself. 

This cupola may be mounted on a truck, as shown in illus- 
tration, or placed upon legs and made stationary if desired. 
In foundries with high roofs it may be charged fiom the top 
and no stack used, but the greatest advantage it presents fur 
very small cupolas is the sectional construction, which admits 
of the lining being repaired or renewed without going into the 
cupola. 

DIMENSIONS. 









c 














No. 


meter 

hell 

iside. 


meter 
iside 
iiiing. 




E >-5 


H^ 1 


-0 1 

■StS 


°J4 

^,2 


s 

s 


E.2.2- 




2 J- «-! 


.2"-! 


u ■4- .xta 


.2^-^ 


.2<:o 


&<-> 


•53 H 


lo 


.2*>"H 




P 


Q 


a 


D 


Q 


Q 


X 


n 


e 


27K 


27" 


22" 


8 ft. 


27" 


39" 


10" 


19" 


4)^x10 


7" 



174 



THE CUPOLA FURNACE. 



Fig. 41. 



STATIONARY BOTTOM CUPOLA. 

In Fig. 41 is shown the old-style English cupola. This 

cupola is constructed upon a 
solid foundation of stone or 
brick work and has a stationary 
bottom of brick, upon which is 
made a sand bottom. The 
refuse, consisting of ash, cinder 
and slag, remaining in the cu- 
pola after the iron is melted, is 
drawn out at the front in place 
of dropping it under the cupola, 
as is now generally done with 
the drop-bottom cupola. These 
cupolas are generally of small 
diameter. The opening in front 
for raking out is about two feet 
square, and when the cupola is 
in blast, is covered with an apron 
of wrought iron. When the 
cupola has been made up for a 
heat, shavings, firewood and a 
small amount of coke are placed 
in it and ignited, with the front 
open ; when the coke is well 
alight, a wall is built up with 
pieces of coke even with the 
inside of the cupola lining. 

Fig. 42. 





STATIONARY BOTTOM CUPOLA. 



SMALL CUPOLAS. I 75 

The bed of coke is then put in, a round stick is placed in the 
spout to form the tap hole, and the front is then filled in with 
new molding sand or loam even with the casing, and rammed 
solid. The apron. Fig. 42, is then placed in position over the 
loam and wedged tight against it, to prevent it being forced 
out by the pressure of molten iron in the cupola. After the 
breast-plate is placed in position, the tap hole and spout are 
made up in the ordinary way. Some melters prefer to place 
the apron in position before lighting the fire, and put the breast 
in from the inside when making up the sand bottom. It is then 
rammed solid against the apron and made up to the full thick- 
ness of the brick lining of the cupola. When the heat has been 
melted the breast-plate is removed and the loam front dug out. 
After the loam front has been broken away, a sheet-iron fender 
is placed in front of the cupola to protect the workmen from 
the heat, and the raking- out process begins. This is done by 
two men with a long two-pronged rake. If the refuse hangs in 
the cupola, it is broken down from the charging door with a 
long bar, or by throwing in pieces of pig iron. These cupolas 
were extensively used in England, but never to any extent 
in this country. 

SMAIX CUPOLAS FOR BEDSTEAD WORK. 

The draw-front cupola has come into use quite extensively in 
the past few years as a bedstead foundry cujjola. This work is 
cast in chills placed in forms for the head or foot of a bedstead. 
After casting a form the castings are removed and pipes placed 
in the chills for another head or foot of a bedstead. This re- 
quires considerable time, and a cupola is theiefore desired that 
will melt iron slow and hot and may be kept in blast all day. 
This cupola possesses this advantage for, in case it becomes 
clogged, the front may be removed and the cupola cleaned out, 
a new front put in, and melting continued without waiting f6r 
the cupola to cool ofif, as with the drop bottom. In a bedstead 
foundry recently visited at Ansonia, Conn., we found one of 
these cupolas in use, with one tuyere 10 inches in diameter lo- 



1/6 THE CUPOLA FURNACE. 

cated at the back of the cupola, with a removable blast pipe. 
When the cupola became clogged or bridged ihe blast pipe was 
removed, the front taken out, and through these two openings 
the obstruction in a few minutes removed with bars. A new 
front was then put in, fresh fuel charged, the blast put on and 
melting resumed in from twenty to thirty minutes from the 
time the blast w<is taken ofif. This cupola, which was a small 
one, was lined with pulveiized or granulated hning material, 
rammed in wiih a cupola lining plug, and was run until the 
lining burned out, the only chipping out being done with bars 
through the front and tuyeres. The lining material used was 
imported from England, but this was only a whim of the man- 
agement, for we have as good lining material for cupolas in this 
country as can be found in England or any other country. 
Any of the other small cupolas before described may be used 
for bedstead work. 

As the cupohis for this line of work are generally of small 
diameter, the charging door should not be pl.iceJ at too great 
a height, as the stock in small cupolas is liable to hang up when 
the door is placed high, and cannot be dislodged with a bar 
from the charging door. The keeping of a cupola in blast all 
day is only a matter of proper charging and sl.igging. When 
this is dt)ne a cupola from twelve inches diameter up to the 
largest size may be kept in blast for this length of time and 
good, hot, fluid iron melted. As every cupola has its peculiari- 
ties in melting, the proper method of charging and fluxing can 
only be determined by experimental melting in it until the 
desired results are obtained. 

CUPOLA ON WHEFLS. 

Fig. 43 illustrates a Paxson truck and track cupola con- 
structed and used in melting iron for making joints in connect- 
ing the ends of rails for trolley road^. This cupola which is 
constructed upon a steel frame was first placed upon ordinary 
truck or wagon wheels as seen in the illustration, and moved 
from place to place by horses, but later on was mounted, upon. 



SMALL CUPOLAS. 



177 



car wheels and moved upon the tracks by trolley power. The 
cupola, which is capable of melting about two tons per hour is 
an ordinary straight cupola with deep bottom and is supplied 
wiih blast from blower, seen on frame, by electric motor, get- 
ting its power ifom overhead trolley wire by means of a wire 
attached to a pole for hooking it over the trolley wire. 

The cupola has no charging door or stack, fuel and iron be- 

FiG. 43. 




PAXSON TRUCK AND TRACK CUPOLA. 



ing thrown in at the top. The V-shaped hood on top is for 
the purpose of throwing escaping heat to the sides and pro- 
tecting the trolley wire seen over it. This cupola is not de- 
signed for use in a foundry, but may be employed for a variety 
of outside work where molten iron can be used to advantage 
if obtainable. 
12 



178 



THE CUPOLA FURNACE. 



SMALL CUPOLAS OF EUROPE. 

In Fig. 44 is shown the type of cupoLns used in the smaller 
foundries throughout the midlands of Great Britain, and in Figs, 
45 and 46 is seen the type of cupolas used in the small foun- 
dries of Belgium and France. It will be observed that these 
cupolas are of the stationary-bottom, draw-front design, from 
which the front is removed and the refuse of melting drawn out 
with a rake or hook. Many of these cupolas are very small, 



Fig. 44. 




and melt iron so slow that a reservoir or tank is provided in 
front of them into which the iron flows as fast as melted, and 
from which it is drawn into ladles for pouring when a sufificient 
amount has been melted to pour the piece to be cast, or a mold 
is made ready for pouring. This system does not admit of very 
hot or fluid iron for light castings, and is only suitable for the 
heavier class of work. No elevators or runways are provided 



SMALL CUPOLAS. 



1/9 



for getting up stock for these cupolas. The stock is carried up 
the steps in boxes or thrown up from one platform to another, 
as was the practice in many of the foundries in this country 

Fig. 45. 




years ago, when cupolas were not constructed of so great a 
height as at the present time. 

Small cupolas are used in the foundries of foreign countries 

Fig. 46. 








to a far greater extent than in this country. In many of the 
smaller foundries it is a practice to mould and pour off at the 
same time. A small cupola is put in blast as soon as a few 



l8o THE CUPOLA FURNACE. 

moulds are ready in the morning, and kept in blast all day. 
This may be an advantage when the moulding- floor space is so 
limited that a full day's work cannot be put up before casting, 
or it is desired to employ a greater number of moulders, but it 
cannot be called good foundry practice, for in carrying and 
pouring iron a different action of the muscles is required than 
in moulding. The eyesight is affected by the molten iron, and 
after pouring a ladle of iron some time is required for it to get 
back into a good moulding state. Time is lost in shaking out 
and tempering sand. The sand is too hot for good moulding, 
the foundry is heated too hot in warm weather, etc. A much 
larger day's work per moulder can be turned out upon the 
American plan of all-day moulding, large cupolas and rapid 
melting. 



CHAPTER IX. 



EXAMPLES OF BAD MELTING. 



Much has been wiitten and published on melting by foun- 
•drymen and foundry foremen, who invariably give an account 
of rapid or economical melting done in their foundries ; and it 
is seldom, if ever, that they publish accounts of poor melting or 
poor heats melted by bad management of their cupolas, or in 
their attempts to reach that perfection in melting of which they 
write. In giving points on melting for the benefit of others, it 
is as essential that causes of poor melting should be known 
that they may be avoided, as it is that those essential to good 
melting should be known that they may be practiced, and we 
therefore present a few instances of poor melting that have 
come under our observation in foundries we have visited, or in 
which we have been called upon to render assistance to over- 
come troubles in melting which were both annoying and ex- 
pensive. In these instances we only give examples of what 
may occur in any foundry, and has occurred in many of them, 
where foundrymen are wholly dependent on their melters. 

In 1878 we were engaged in making some experiments in 
melting with oil at the stove foundry of Perry & Co., Sing Sing, 
N. Y., at that time the largest stove works in the country. 
They were melting from 50 to 60 tons per day in four cupolas 
entirely with convict labor, and the results in melting were 
very unsatisfactory. Mr. Andrew Dickey, one of the firm and 
manager of the works, came to us one day after some very bad 
heats and asked us to take charge of their cupolas, set our own 
wages, and carry on our experiments at the same time. We 
took charge of their cupolas the following day and soon had 
their melting going along smoothly, but we did not like the 
job, and suggested to Mr. Dickey that we should teach a man 

( 181 ; 



1 82 THE CUPOLA FURNACE. 

to melt who could take our place when we were ready to leave, 
and this he consented to do. A man was selected who proved 
an apt scholar, and we soon had him instructed in all the 
details of melting, and when we left he took full charge of the 
cupolas. 

Two years later we received a despatch from Perry & Co., 
stating that they wished to see us as soon as possible at their 
Sing Sing Works. Upon our arrival there late in the afternoon, 
Mr. Dickey informed us they were having trouble with all their 
cupolas, and it had been impossible of late to get a good heat 
out of any of them, and wished us to see what was the trouble. 
We found the same man in charge whom we had two years 
previously taught to melt, and inquired of him what the trouble 
was. He said he did not know, that he had fully followed our 
instructions and had no trouble in melting until within the last 
few weeks; during this time the cupolas had been melting 
very badly.. He had increased and decreased the fuel in the 
bed and charges, increased it in one part of the heat and de- 
creased it in another, varied the amount of iron on the bed and 
in the charges, but had been unable to locate the trouble. We 
asked him to describe how the cupolas melted, and he said they 
melted the first few tons, which was about the first two charges, 
fast and hot ; after that the melting gradually grew slower until 
near the end of the heat, when melting almost ceased ; the 
cupolas were so bunged up every heat that they could scarcely 
be dumped, and it was only after a great deal of labor with bars 
that a hole could be gotten through, so that they would cool oft" 
by the next morning. The iron was of an uneven temperature, 
frequently too dull for pouring and in some parts of the heat 
white hard, although nothing but soft iron had been charged. 
He thought the trouble must be in the blast — that old " no 
blast" story that foundrymen hear so often, when melters do 
not know how to manage a cupola and have to lay the blame 
on something. We informed him that the trouble could not be 
in the blast, or the cupolas would not have melted the first two 
charges fast and hot; that the trouble was the stock logged in. 



EXAMPLES OF BAD MELTING. 

Fig. 47. 



183 





SECTIONAL VIEW. LINING OUT OF SHAPE. NO. I. 



1 84 THE CUPOI.A FURNACE. 

settled or settled unevenly after melting the first two charges, 
which was the cause of the uneven melting in the latter part of 
the heat, and he must have permitted the linings to get into a 
shape that produced this condition in the cupolas. He did not 
think this possible, for he had followed our direction for shap- 
ing a lining, but admitted that he frequently found pieces of 
unmcltcd pig and scrap in the cinder above the tuyeres when 
chipping out, which confirmed our theory, and we looked no 
further for the cause of poor melting. 

The following morning the cupolas were almost closed up 
with cinder, slag and iron, and after a gieat deal of labor in 
breaking down and chipping out we found the linings in the 
shapes shown in Figs. 47 to 50. 

Cupola No. 1 had not been lined for a long time, and the 
lining was burned away until it was very thin all the way up. 
This did not prevent the cupola melting but should have made 
it melt faster; for as a cupola is enlaiged in diameter by burn- 
ing out of the lining its melting capacity increases; but in this 
case the meltcr had permitted the lining to become hollow 
around the cupola just above the tuyeres. When the stock 
settled, that on the outer edges logged in this hollow, became 
chilled and threw the blast to the centre of the cupola. After 
a few tons had been melted the chilled stock over the tuyeres 
increased rapidly until the melting was restricted to an open- 
ing in the centre, which gradually closed up with the fan blast, 
and the longer the cupola was run the slower it melted, until 
melting ceased altogether. 

In No. 2 the lining was not burned away to so great an ex- 
tent as in No. 1, but the melter had permitted it as in No. i to 
become hollow over the tuyeres. He had been troubled with 
molten iron running into the tuyeres, and to prevent it doing 
so had built the lining out from 3 to 4 inches with daubing over 
each tuyere. This cupola like the others was 60 inches in 
diameter with six oval tuyeres each 4 by 12 inches laid flat. 
Over each of these tu}'eres was a projecting hump 3 to 4 inches 
thick and 16 to 18 inches long; add to the thickness of these 



EXAMPLES OF BAD MELTING. 



185 



Fig. 48. 




SECTIONAL VIEW LINING OUT OF SHAPE. NO 2. 



1 86 THE CUPOLA FURNACE. 

humps a hollow in the lining of 4 to 6 inches, and a shelf from 
8 to 10 inches wide was formed over each tuyere upon which 
the stock could not help lodging, and could not be melted 
after lodging. When the cupola was first put in blast it melted 
very well, but after the stock began to lodge gradually, melted 
more slowly until it finally bunged up. The convict who had 
charge of this cupola informed me that every day, when chip- 
ping out, he found pieces of pig iron and unburned coke lodged 
over the tuyeres, and molten iron frequently ran into the 
tuyeres when melting. To prevent this, he had gradually built 
the lining out over the tuyeres (from day to day), until the 
shape we have described was reached ; but it neither prevented 
the stock lodging nor the molten iron flowing into the tuyeres, 
but increased the trouble. 

No. 3 (Fig. 49) had recently been newly lined, and melted dif- 
ferently from the other two cupolas. It was in a better shape over 
the tuyeres, and the trouble in melting was not caused by the 
hanging up of the stock from lodgment over the tuyeres, but 
by the escape of blast around the lining. The cupola had been 
lined with 9-inch brick and its diameter greatly reduced by the 
heavy lining, and as a result the cupola melted more slowly 
than with the old lining. To make it melt faster, the melter 
had chipped it out very close every day and permitted the 
lining to burn out to enlarge the cupola at the melting point. 
This would have improved the melting had the belly in the 
lining been given a proper shape; but no attempt had been 
made to shape it, and the lining was burnt out to a depth of 
from 4 to 6 inches, with a sudden offset from the small to the 
large diameter. The stock did not expand in settling to fill 
the sudden enlargement, and a large part of the blast escaped 
into the belly and re-entered the stock above the melting zone. 
This naturally threw the heat against the lining at the top of 
the belly and cut it out very rapidly, and would have ruined 
the lining in a week's time had the cupola been permitted to 
continue to work in this way. The belly in the lining was filled 
with stock when charging, and the melting was very good until 



EXAMPLES OF BAD MELTING. 
Fig. 94. 



187 




SECTIONAL VIEW LINING OUT OF SHAPE. NO. 3. 



1 88 THE CUPOLA FURNACE. 

the stock settled and the blast began to escape in the manner 
described, when it rapidly grew slower until it stopped alto- 
gether, and this cupola which had been relined to make it melt 
better was the poorest meking one of the lot. 

In Fig, 50 the lining had been permitted to belly out over the 
tu)'eres at a very low point and a shelf formed, upon which the 
stock lodged by building the lining out over the tuyeres, but the 
humps over the tuyeres were not so long as those in Fig. 48, 
and the stock had settled between the tuyeres to a greater ex- 
tent than over them. This uneven settling of the stock had 
thrown the heat against the lining at different points and burnt 
it out in holes all the way up to the charging door. 

Here were four cupolas, all of the same diameter, having the 
same number of tuyeres, with the lining of each one in a dif- 
ferent shape, but all having the same objectionable feature — a 
hollow in the lining over the tuyeres, which was the real cause 
of bad melting. We had all the humps over the tuyeres chipped 
off and the linings daubed up perfectly straight for six inches 
above the top of the tuyeres, all around the cupola, and filled 
in the lining above with split brick and daubing, giving each 
cupola the shape indicated by the dotted lines. The cupolas 
were then charged as they were before the ti-ouble began, and 
each one melted hot, even iron throughout the heat and dumped 
clean. As soon as the man we had taught to melt saw us shape 
up a small section of the lining, he said : " Why, you told me to 
keep the linings in that shape and showed me how to do it two 
years ago." We said :" Why did you not do it? " He said he 
had forgotten it, and when the cupolas began to work badly, 
did not knew what to do, and in fact had lost his head and let 
every melter under him do as they thought best. This is fre- 
quently the case with good melters. They forget points that 
they have learned in melting, have no literature upon the sub- 
ject from which to refresh their memories, or melters to con- 
sult who are competent to advise, and gradually drift into a 
routine of work, and when anything goes wrong with the melt- 
ing do not know how to overcome the difficulty. 



EXAMPLES OF BAD MELTING. 
Fig. 50. 



189 




SECTIONAL VIEW OF LINING OUT OF SHAPE. NO. 4. 



IQO THE CUPOLA FURNACE. 

BAD MELTING AT A WEST TROY STOVE WORKS. 

In 1882 we visited the foundry of Daniel E. Paris & Co., 
West Troy, N. Y., and while waiting for Mr. Paris, looked over 
the cupola. We found the lining in a condition indicating very 
poor melting, and knew they were having some trouble with 
their iron. When Mr. Paris returned and learned who we were, 
he informed us that their foundry had recently burned down and 
they had moved into the present one, which had for some time 
before been idle. The boiler and engine were small and they 
were having some trouble in melting for want of power to drive 
a Sturtevant blower, which when run at a proper .speed was 
large enough for the cupola. They were also endeavoring to 
melt up a lot of scrap from their recent fire, and had also pro- 
cured some of the best brands of No. i Pennsylvania irons and 
Scotch pig to melt with it, but were having some hard cast- 
ings. He wished to know if we could suggest anything to help 
them out until they could put in a new engine and boiler, and 
find some softer pig iron to work up the scraps, and he took us 
out to look over the works to see what change could be sug- 
gested. 

We looked over the blower and machinery, which were only 
those employed in stove moulding, and then went into the 
engine and boiler room, where we found a good-sized engine 
and boiler, and decided that they were large enough to run the 
blower and all the machinery in the works at the same time. 
The engineer at once informed us that they were too small and 
he could not run any of the mounting machinery when the blast 
was on, or pump water into the boiler, without reducing the 
speed of the blower, and he had to fill the boiler and stop the 
engine for half an hour before putting on the blast, to get up 
steam. We then went into the foundry, where we found a well 
arranged cupola of fifty-four inches diameter inside the lining, 
and learned that they were melting about eight tons of iron 
each heat ; that from four to four and a half hours were re- 
quired to run off the heat, and they were melting seven pounds 
of iron to the pound of anthracite coal. The iron melted so 



EXAMPLES OF BAD MELTING. 191 

slowly that it was difficult to catch four hand-ladles full to 
pour off a /oiir tip before the first ladle-full was too dull to 
run the work, and the iron was sometimes so hard that the 
plate cracked when taken out of the sand or when knocking 
olT the gates. 

We then went upon the scafifold, where we found the coal 
when charged was not weighed, but measured in a basket and 
dumped from the basket into the cupola. We afterwards 
weighed a basketful of coal filled as the melter generally filled 
it, and found it weighed almost twice as much as the melter 
stated, and with the extra weight of coal in the basket and the 
extra shovelfuls the melter said he threw in to fill up holes, we 
concluded that they were melting about three pounds of iron 
with one of coal, in place of seven to one as claimed by the 
melter. No slate was used in charging, sprews and gates were 
not weighed, but the weight estimated by counting the shovel- 
fuls, and pig was weighed by counting the pieces, estimating 
four pieces to the hundredweight. The greater part of the 
coal, when dumped into the cupola from the basket, fell 
directly under the charging door, where it remained ; and the 
greater part of the iron naturally went to the opposite side of 
the cupola, and this uneven charging naturally produced un- 
even melting. 

We pointed out to Mr. Paris that his cupola lining was not 
glazed in front of the charging door, but was rough and jagged, 
as linings generally are in cupola stacks, which is an indica- 
tion that too great a quantity of fuel is being consumed in 
melting and that by using less coal better melting would be 
done. He thought seven to one was very good melting and 
knew none of the foundries in Troy were doing any better, and 
did not think iron could be melted sufficiently hot for their work 
with a greater ratio of iron to fuel than was being consumed in 
their cupola. But he was getting very poor results in melting, 
and after considerable talk he concluded to let us try a heat the 
following day with less fuel. 

The following morning when we went round to have the 



192 THE CUPOLA FURNACE. 

cupola prepared for a heat, we found the matter of less fuel had 
been talked over by the entire foundry force and by them con- 
demned. They argued that dull iron had been mel'ed with the 
quantity of fuel used, and could not be poured at all if less fuel 
were used. It is a curious fact that moulders working piece 
work and losing work every day from dull iron will object to a 
stranger, and any man whatever but the mclier making any 
change in the management of the cupola, or as they term it, 
experimenting with the cupola. While getting the cupola ready 
for a heat, the moulders came to us at the cupola or in the 
yard, one after another, and asked us all kinds of questions 
about melting, and Mr. Paris came also and asked us if we 
were sure we could melt iron hot enough for their work with 
less fuel than they were using, also if we had ever done so 
before ; and we found that we would have to be very careful 
what we said or did, or we would not be permitted to run ofif a 
heat. 

The melter was an old hand, who had melted iron in a num- 
ber of the foundries in Troy, and was considered good. He 
was very much opposed to having us do any better melting in 
the cupola than he had done without a new engine and boiler,, 
which he declared must be put in before anything better 
could be done. He knew all about it, and to teach this man to 
melt with less fuel would only be a waste of time, for he would 
probably in less than a week drift back into the same old rut if 
not closely watched, and would condemn our way of manag- 
ing a cupola. So we told Mr. Paris we could teach his fore- 
man to melt in a few days so that he could oversee the work 
and teach a man to do it in case his melter was sick or quit, 
and that it would be much better for them than for us to show 
their melter how to work with less fuel. After consulting the 
foreman it was decided that we should teach the foreman, and 
he went on the scaffold with us. He had the cupola made 
up as we directed, sent to a store and purchased a new slate 
and arranged a system of mixing and chaiging the iron so that 
it would produce an even grade when melied, having had the 



EXAMPLES OF BAD MELTING, 1 93 

scales dug out of a pile of rubbish in a corner and cleaned up, 
and the iron and fuel placed conveniently for charging. 

After everything had been arranged for the heat we had a 
little time to spare, and made it a point to see some of the lead- 
ing moulders and explain to them that we had shaped the 
lining so that the cupola would melt faster and with a little less 
fuel than they had been using, and make hot iron. We also 
saw the engineer and informed him that we would charge the 
cupola in a way that it would demand less blast, and if he filled 
his boiler and had a good head of steam on just before putting 
on the blast, he could run all the machinery required for mount- 
ing when the blast was on. These explanations seemed to 
satisfy everybody, and the foreman was so enthusiastic in learn- 
ing to melt that we had no further fear of being run out of the 
works, and were looked upon as the man who understood his 
business until the heat was all charged into the cupola, when 
the melter went into the foundry and said to the moulders : 
" Be jabers yees will not pour off to-day boys, for that cupola 
will not make hot enough iron for yees with all the coal I was 
after putting in. and that man has left out half of the coal I put 
up for the heat. Yees may as well go home and save your 
moulds for to-morrow's heat; for yees will not run your work 
to-day." 

From that time until the blast went on, we were looked at 
shyly by all the moulders except two, who had seen us melt in 
other foundries; but the foreman and these two assured them 
that we understood our business and they would have a good 
heat, which probably saved us from being driven out; for there 
was a tough lot of stove-moulders in Troy in those days, who 
considered their rights sacred and that no punishment was too 
great for any man who encroached upon them. 

When the blast was put on, the moulders gathered round the 
cupola and watched every tap until the iron came down so hot 
and fast that the first turn could not handle it, and the second 
turn was called up, and they were all kept on the run until the 
end of the heat. Getting iron so fast and hot was something 
13 



194 THE CUPOLA FURN.^CE. 

the moulders had never been used to in that foundry, and a 
number of them wished to know if we were trying to kill them 
all by giving them the iron so fast. But all were delighted 
with getting hot iron to pour ofT their work and getting through 
so early ; and as we went along the gangways to see how the 
castings were turning out, a number of them asked us to wait 
until they were shaken out and have a glass of ale with them, 
which was the great drink of the Troy moulders. Had we 
waited for them we probably would not have reached our hotel 
that evening, for almost all of them dropped into a nearby 
saloon after they were through with their day's work, and we 
should have been asked to drink with every one of them. 

In this heat we had used considerably more coal than we 
considered necessary, as we were not familiar with the working 
of the cupola and desired to be on the safe side and make hot 
iron, even though the melting was a liltle slow, which was the 
case. Two hours were required for the heat, but even this 
length of time was fully two hours better then they had been 
doing, and all the machinery required for mounting was run 
during the heat without stopping the engine for half an hour to 
get up steam before putting on the blast. 

On the following day we reduced the coal a little more, and 
on the third day reduced it until we were melting six and a half 
pounds of iron to one of coal, and the heat was melted in one 
hour and thirty minutes. This was as fast as the moulders 
could handle the iron ; and as we did not consider it safe to 
melt iron for stove plate with less fuel, although we could have 
done so, and they did not desire it melted any faster, we made 
no further attempt to save fuel or reduce time of melting. 

The foreman learned very rapidly, and at the end of three 
days was fully competent to oversee the work, and they had no 
further trouble in melting or with hard iron, and were able to 
melt up all the scrap from their recent fire with the brands of 
pig iron they had on hand, and it was not found necessary to 
put in a larger engine and boiler to get a sufficient blast, after 
they had learned how to manage the cupola. 



EXAMPLES OF BAD MELTING. 1 95 

The cause of bad melting in this foundry was plainly indi- 
cated to an experienced melter at first glance by the lining in 
front of and around the charging door; namely, too great a 
quantity of fuel in the cupola and too small a volume of blast 
for that fuel. So large a quantity of fuel was charged for a bed 
that the iron placed upon it did not come within the melting 
zone, and could not be melted until the surplus fuel burned 
away and permitted it to settle into the zone. Each charge of 
fuel to replenish the bed was too heav}-, and the greater part of 
it had to be consumed before the iron placed upon it was per- 
mitted to enter the melting zone, and the slow melting was due 
to the time required in consuming the surplus fuel before the 
melting could take place. The hard iron in parts of the heat 
was due to uneven charging, which permitted the scrap at times 
to be melted by itself and drawn from the cupola without being 
mixed with melted pig, and the entire mass of iron was 
hardened by being subjected for a long time to a high degree 
of heat before it was permitted to enter the melting zone and 
be melted. 

To increase the volume of blast the speed of the blower had 
been increased to fully double the number of revolutions per 
minute given in the directions for running it; but the volume of 
blast had been decreased in place of being increased, as was 
supposed it had been by the increase of speed, and the cupolas 
received less blast. 

We had no means of definitely determining to what extent it 
was decreased, but from the appearance of the blast in the 
cupola at difTerent stages of the heat, before and after decreas- 
ing the speed of the blower, we concluded that the volume of 
blast was increased fully one-half, by running the engine at its 
normal speed and reducing the speed of the blower to the 
number of revolutions given in the directions for running it. 

This is one of the cases where the cupola air-gauge in com- 
mon use would have been of value, for it would have indicated 
a high pressure of blast before the speed of the engine was 
increased, and located the trouble at the cupola in place of at 
the engine. 



196 THE CUPOLA FURNACE. 

WARMING UP A CUPOLA. 

In 1 88 1 we visited the plant of the Providence Locomotive 
Works, Providence, R. I. The superintendent, Mr. Durgon, we 
believe was his name, wished to know if we were the Kirk that 
wrote " The Founding of Metals." We informed him that we 
were, and he replied that we might know all about a cupola, 
but our directions there given for constructing a cupola were 
no good, for he had constructed a cupola on that plan and it 
was a complete failure. It would not make hot iron, or melt 
half the amount per hour stated, or melt the heat before bridg- 
ing over and bunging up. We informed him that if he had 
constructed the cupola exactly on the plan given it would do 
the work stated it would do. He invited us to go into the 
foundry and look the cupola over, and if it was not right he 
would make it right. We accepted the invitation and looked 
the cupola, blower and pipes all over, and could find no fault 
with them. The cupola was in blast at the time and we 
watched it melt for an hour; it certainly was a complete failure. 
The iron from the beginning to the end of the h( at was dull, 
the melting slow, and the castings dirty and much harder than 
they should have been with the quality of iron melted. 

We knew that the trouble lay in the management of the 
cupola, and decided to go round the next day and see the 
melter make it up for a heat. This the superintendent de- 
cided to let us do, although he thought he had the best melter 
in New England and the trouble could not be in the manage- 
ment of the cupola. On the following day we were on hand 
early and found the cupola badly bridged and bunged up. 
The melter soon had it chipped out and daubed up in good 
shape, and we saw that the trouble was not in the shape of the 
lining. He then put in a very nice sand bottom from which 
there could be no trouble in melting. He next put in shav- 
ings and a large quantity of wood, which he burned to dry the 
daubing. After this had been dried he added more wood and 
a good bed of hard coal, which he burned up to warm the 
cupola for melting; and he certainly did give it a good warm- 



EXAMPLES OF BAD MELTING. 197 

ing, for when the doors were opened for charging the Hning 
was heated to a white heat from the bottom to the stack. He 
then added a httle more coal to level up the bed, and began 
charging. 

As soon as we saw the extent to which, the lining had been 
heated and the bed burned, we knew that the cause of the poor 
melting lay in the bed. In warming the cupola up for melting 
the life had all been burned out of the coal, and but little of it 
was left to melt with. The cupola was filled with ashes below 
the tuyeres, and even if iron was melted hot it would be chilled 
in its descent through these ashes to the bottom of the cupola. 
The fuel thrown in just before charging was flaked off, broken 
and burned up by the intense heat almost before the iron could 
be charged, and had it not been that an extra high bed was put 
in before warming-up not a pound of iron would have been 
melted. 

We had frequently seen beds burned too much, but had never 
seen one burned to the extent of this one, or a cupola heated 
so hot before charging, and we stayed on the scalTold during the 
filling of the cupola with stock to see if the intense heat in the 
cupola had any effect upon the stock that would improve the 
melting in any way. The first charge seemed to be heated to 
: a considerable extent by the hot lining and bed, and prepared 
for melting. After this charge was put in the cupola cooled off 
very rapidly, and before it was filled there was scarcely any 
perceptible heat at the charging door, and the stock could not 
have been heated to any extent above the first or second 
charge, by warming of the cupola. When the cupola had been 
filled the blast was put on, and the iron melted exactly as we 
had seen it do the day before, dull and slow. The cupola had 
been properly made up ; plenty of fuel had been put in to make 
hot iron ; charges of fuel and iron were of about the right pro- 
portion, and had been properly placed in charging, and there 
could be no doubt that the trouble in melting lay in the bed, 
as before stated. 

The following day the superintendent put the melter on the 



19^ THE CUPOLA FURNACE. 

Other cupola and gave us full charge of the one constructed on 
our plan. We had it made up in about the same way as the 
melter did ; put in our shavings, wood and all the bed, but 
a few shovelfuls to level up with before lighting up. After light- 
ing up we waited until the heavy smoke was burned off and 
the fire began to show through the top of the bed. We then 
leveled up the bed and began charging. The only change we 
made in charging was to reduce the fuel in the bed about one- 
fourth, and that in the charges a little. When the blast was 
put on iron came down in about ten minutes, melted fast and 
hot throughout the heat, and the same amount of iron was 
melted in one-half the time it had been the previous day. This 
convinced the supermtendent that the cupola was all right, for 
it did all we claimed it would do and a little more, and it con- 
vinced us that there was nothing to be gained in melting by 
warming up a cupola before charging. 

BAD MELTING CAUSED BY WOOD AND COAL. 

In one of the leading novelty foundries in Philadelphia that 
we visited some years ago they were employing two cupolas, 
one 40 inches and the other 30 inches inside diameter, to melt S 
tons of iron, and it was very difficult to melt that amount in these 
cupolas. We knew that something was wrong, and went upon» 
the scaffold to look into the cupolas and found the melter just 
putting in the wood for lighting up. He had put in quite a 
lot of finely-split wood, and had another barrow ready to add. 
After this was in, he went down and got three more barrows 
of cord-wood sawed in two and added this, and then some long 
wood, and when he had it all in, the cupola was filled to the 
bottom of the charging door. He then filled the cupola with 
coal to the top of the charging door, putting in the largest 
lumps he could find. We asked him why he put in so large a 
quantity of wood, and he said it was necessary to light the coal ; 
and we presume it was, for some of the pieces of coal were as 
large as he could lift and place in the cupola, and it would re- 
quire considerable heat to start a fire with such large coal ; and 



EXAMPLES OF BAD MELTING. 1 99 

he said they could not melt with any smaller coal. We tried 
to convince him that the cupola would melt better with less 
wood and smaller coal ; but this was impossible, for he was an 
old melter and knew all about it. 

Either one of these cupolas would have melted the amount 
of iron they were getting in the two, and in less time, had they 
been properly managed ; but this was not done, and the firm 
afterwards put in two Colliau cupolas to do the work. The 
cause of poor melting in these cupolas was too great a quan- 
tity of hard wood, which took a long time to burn out, and in 
burning out the bed was burned to so great an extent that the 
cupola was filled with wood ashes and coal ashes before melt- 
ing began. The large lumps of coal also contributed to the 
poor melting by making an open fire through which the blast 
escaped freely without producing a hot fire, such as would have 
been produced by smaller coal. 

POOR MELTING IN A CINCINNATI CUPOLA. 

In Fig. 51 is seen a sectional elevation showing the condition 
of a small cnpola we' saw in Cincinnati, Ohio, a few years ago. 
This cupola would not melt, the founder said, and could not be 
made to melt. He had put in a new fan, and now his melter 
wanted a blower, and said the cupola would not melt without a 
forced blast. We examined the cupola, and suggested to the 
founder that he needed a new melter worse than a new blower. 

The cupola had not for a long time been properly chipped 
out, and a belt of cinder and slag varying in thickness from four 
to six inches had been permitted to adhere to the lining above 
the melting point, and another belt of cinder and slag pro- 
jected from the lining. Between these two projecting belts the 
lining had burned away, making a deep hollow at the melting 
point. Entirely too much fuel had been consumed in melting, 
or the belt of cinder and slag could not have formed above the 
melting point. 

We had all the projecting humps chipped off and the hollows 
filled in with fire-brick and daubing, so as to give the lining an 



200 



THE CUPOLA FURNACE. 
Fig. 51. 






ILLUSTRATION OF BAD MELTING, 



EXAMPLES OF BAD MELTING. 20I 

even taper. The cupola was then properly charged, and there 
was no trouble in melting iron hot and fast. 

UNEVEN BURNING OF THE BED. 

We were once compelled to dump a cupola at the foundry of 
Perry & Co., from the carelessness of the melter in placing the 
shavings and wood in the cupola in such a way that they did 
not light up the fuel evenly, and in putting on the blast when 
the bed was only burned up on one side. We had not noticed 
it, and he thought the blast would make it burn up on the other 
side. This it did not do, and after the cupola had been in blast 
a short time it had to be dumped. 

The careless way in which shavings and wood are often 
thrown into a cupola from the charging door frequently causes 
an uneven burning of the bed and bad melting. We had a 
number of poor heats in our own foundry, due to this kind of 
carelessness, before discovering the cause of them. 

We might relate many more examples of poor melting in 
various foundries, but these will probably suflfice, as the causes 
of poor melting when a cupola is properly constructed will 
generally be found in the shape of the lining, burning of the 
bed, or quantity of fuel used in melting, examples of which 
have here been given. 



CHAPTER X. 



HOT-BLAST CUPOLAS. 



Probably ever since the introduction of the hot blast into 
blast-furnace practice attempts have been made by founders to 
apply it to their cupola practice. Many illustrations of appa- 
rent success, but final failure, in this direction might be quoted, 
but a few examples of the most promising of success will prob- 
ably be sufficient to illustrate the fallacy of the theory and pre- 
vent others from going over the same ground that has already 
been tried in these endeavors to solve the problem of hot blast 
as is being done at the present time. This problem can readily 
be solved by constructing a hot blast oven similar to that of the 
blast furnace before the introduction of the present gas-heated 
oven, but this oven must be heated before the cupola can be 
put in blast with a hot blast and kept at a high temperature 
during the heat with fuel other than that used in melting. It 
can readily be seen by any practical founder that this system is 
entirely too expensive for a cupola only in blast for a few hours 
per day, or even all day. And the saving effected in cupola 
fuel and benefits derived from a hot blast would not justify such 
a plan for heating the blast. For this reason the plan has never 
been tried to our knowledge, and all the work done in this 
direction that has come to our notice has been with a view of 
utilizing heat from the cupola after it had done its work in 
melting, or heat escaping from the cupola stack. 

Probably one of the best and most complete methods of 
utilizing this heat ever devised is that shown in Fig. 52. This 
pair of cupolas were constructed at Albany, N. Y., by the firm 
of Jagger, Treadwell & Perry. With a view of saving fuel and 
improving the quality of iron for light work, the two cupolas 
DD, of thirty and forty-five inches diameter, respectively, inside 

( 202 ) 



HOT-BLAST CUPOLAS. 
Fig. 52. 



203 




HOT BLAST CUPOLAS. 



204 THE CUPOLA FURNACE. 

the lining, and eight feet high, were constructed of boiler 
plate ; the top and bottom plates between which the cupolas 
were placed were sqpported by four iron columns, and on the 
top plate were fitted the brick arches BB, which connected the 
cupolas with the brick ovens EE. In the rear of each cupola, 
between the ovens, was placed the high stack A. Each oven 
was filled with cast-iron pipe CC, through which the blast 
passed before entering the cupolas. When in blast, the escaping 
heat from the cupolas passed downward through the ovens as 
indicated by the arrows, and entered the stack A from the bot- 
tom of the ovens. The pipes were by the escaping heat from the 
cupolas heated to a red heat, and the blast in passing through 
these coils of pipe was heated to a sufificient degree to melt lead 
before entering the cupolas. This plan was a success so far as 
heating the blast was concerned, but the blast could not be 
heated up to the above degree until the cupolas had been in 
blast for some time. Hence very little fuel was saved, for no 
economy in fuel could be effected until the blast was heated, 
and the cupolas had to be fully charged with fuel for the first 
half of the heat. No perceptible improvement was made in the 
quality of the iron by the heating of the blast, and the greatest 
objection to these cupolas was the difficulty of keeping the coils 
of pipe intact. The heating of the pipe to a red heat every 
time the cupolas were put in blast and permitting them to cool 
before the next heat, in a short time destroyed the cohesive 
properties of the iron, and the pipe frequently broke after or 
during a heat and permitted the blast to escape into the oven. 
These breaks became so frequent and annoying after the pipe 
had been in use for a short time, and were so expensive to re- 
pair, that the slight saving effected in fuel did not justify a con- 
tinued use of the hot blast, and it was abandoned. The cupolas 
were for a long time used without the hot blast, and the ovens 
proved excellent spark catchers. No sparks were ever thrown 
from the top of the high stack, and the ovens had frequently to 
be cleaned to remove them. 

It will be observed that these cupolas were only eight feet 



HOT-BLAST CUPOLAS. 205 

high which is very low as compared with the height of cupolas 
of these diameters at the present time, and a great deal more 
heat escaped ; yet the blast was not heated to any great extent 
until half of the heat was melted, and the cupola had been in 
blast for an hour. With the present height of cupolas, from 
which very little heat escapes as long as the cupola is kept 
filled with the stock to the charging door, it is doubtful if blast 
cojLild be heated at all in an oven of this construction before the 
very end of a heat when the stock gets low in the cupola and 
permits heat to escape up the stack. Several attempts have 
been made to take the escaping heat direct from the top of a 
cupola and return it into the cupola through the tuyeres; but 
in all cases this plan has, for lack of means to force the hot air 
into the cupola, proven a failure. 

Exhaust pipes have been connected with the stack of 1 cupola 
and the inlets of the blower placed near the cupola, and hot air 
drawn from the stack by the blower and returned to the cupola 
through the tuyeres. This arrangement supplied a hot blast to 
the cupola with no expense for heating the blast, and was in the 
early part of a heat in which it was tried, a success, when only 
a small amount of heat escaped from the cupola and the air 
drawn from the stack was heated only to a limited extent. 
But, as the melting progressed and the stock settled low in the 
cupola, the air drawn from the stack was heated to so high a 
degree as to heat and destroy a blower through which it was 
passed in being returned to the cupola. Cculd hot air have 
been taken from a cupola stack and returned to the cupola 
through the tuyeres without passing it through a blower, it 
would, no doubt, have efifected a great savmg in fuel in the days 
of low cupolas, when a large amount of the heat from fuel direct 
was not utilized in melting. But this could not be done, and 
after a number of experiments to secure a hot blast in this way, 
the plan was given up as a failure. 

THE COLLIAU HOT BLAST CUPOLA. 

This cupola was designed by M. Victor Colliau, the man who 



206 THE CUPOLA FURNACE. 

first introduced the double-tuyere cupola into this country from 
France. This cupola, one of which was installed in the Tacony 
Iron Works, Philadelphia, Pa., was of the Colliau double- 
tuyere design, to which was added a belt air chamber extend- 
ing from the cupola bottom plate to near the charging door. 
Blast was forced into the chamber at the top and entered the 
cupola from the chamber through the tuyeres near the bottom. 
By holding the blast for a short time in contact with the cupola 
shell, which always becomes heated to a greater or less extent 
when the cupola is in blast, it was hoped to heat the blast before 
entering the tuyeres, but it was soon found that the heat escap- 
ing through the shell, although considerable in a four-inch lin- 
ing cupola, was not sufficient to heat the blast to any percepti- 
ble extent. This was probably one of the most deceptive 
designs for a hot-blast cupola ever conceived, for it was easy 
to convince the founder by inducing him to place his hand in 
contact with the shell that heat escaped, especially from a 
thinly-lined cupola, and it was difificult to determine the extent 
to which the blast was heated in this air belt before entering 
the tuyere. The present design of Colliau cupolas, with the air 
chamber extending from the bottom plate to a height of prob- 
ably three feet, is still designated by a number of cupola manu- 
facturers as the Colliau hot-blast cupola. And many founders 
who have never stopped to investigate are under the impres- 
sion they are getting a hot blast, which is not the case. 

THE HOLLAND CUPOLA. 

The Holland cupola, which is classed as, or claimed to be a 
hot-blast cupola, was first exhibited in this country, in a foundry 
at Elizabethport, N. J., about 20 years ago. Some years later 
it attracted attention at Pittsburg, Pa., and again has made its 
appearance at Syracuse, Ind. In these various exhibits and 
tests it has always been pronounced a success, but for some 
reason it has not been adopted by foundrymen or come into 
general use as a foundry cupola. Its design has been changed 
to a considerable extent since its first exhibition, and now pre- 



HOT-BLAST CUPOLAS. 



207 



sents the construction shown in Fig. 53, for which the following 
claims are made : 

" The Holland cupola overcomes the existing trouble now so 



Fig. 53. 




208 THE CUPOLA FURNACE. 

universal in almost all foundries. Our plan is extremely simple 
and when investigated reveals a scientific discovery for the bet- 
terment of all iron workers. The appliances can be connected 
with any ordinary cupola now in service. The results obtained 
from the use of the Holland, are outlined in the following explan- 
ation : The hot blast, capable of attaining a very high tempera- 
ture, is produced by locating a heating tank in the cupola stack 
immediately above the charging door and connected with the 
air compressor or a fan. The cold air is discharged into the 
bottom of the tank, thus protecting the same from melting or 
blistering by the high temperature of the escaping gases from 
the cupola blast. The two pipes conducting the superheated 
air from the tank to the tuyeres are larger in area than the 
cold-blast pipe, thus causing free circulation from the tank." 

It is here claimed that the cold air is discharged into the 
bottom of the tank, thus protecting the same from melting or 
blistering by the high temperature of the escaping gases from 
the cupola blast. This tank, located in the cupola stack, ap- 
pears to be the only point in the construction at which the 
blast can be heated, and if this is kept cool by the blast, how 
is the blast heated? Then again the tank would appear to any 
practical man to be entirely too small to heat the thousands of 
cubic feet of air required to melt iron in a cupola, even if this 
tank were heated to a white heat. In the days of hot-blast 
pipe for blast furnaces hundreds of feet of pipe heated to 
almost the melting point of the metal were required to heat the 
blast, even to a degree far beloW that obtained by the hot-blast 
stoves used for this purpose at the present time. Another 
objection to heating blast in this way is the fact that so little 
heat escapes from a properly constructed cupola that, when 
filled with stock to the charging door, and in blast, the hand 
may be held in the cupola at this point without danger of burn- 
ing, and so far as heat is concerned a man might stand upon 
the stock in the larger cupolas while the cupola is melting 20 
tons per hour. 

This being the case, what possible chance is there of even 



HOT-BLAST CUPOLAS. 209 

warming the blast upon this plan before the end of a heat, 
when the stock gets low in the cupola and a hot blast would 
be of no advantage. This theory of heating the blast was ex- 
ploded years ago, and described in my work of 1877, and again 
in the first edition of "The Cupola Furnace" as follows: At 
the stove foundry of Ransom & Co., Albany, N. Y., a cupoLi 
was constructed wiih a large stack, and coils of pipe for heat- 
ing the blast were placed in the stack directly over the cupola. 
The blast when parsed through these pipes was heated to a 
high degree after the cupola had been in blast for a short time, 
but the pipes in this case broke after repeated heating and 
cooling, as in the ovens of the J^'gger, Treadwell and Perry 
cupolas, and after the killing of a meltcr, by a piece of pipe 
falling upon him from the stack while picking out the cupola, 
the pipes were all removed from the stack and heating of the 
blast was discontinued. 

OIL IN CUPOLA PRACTICE. 

In addition to the claims made for a hot blast in the Holland 
Cupola, the following claims are made for the use of oil, in- 
jected into each tux-ere with the blast from the oil tank through 
pipes as shown in the illustration. 

*' The hydrocarbon gas produced by mixing air and oil under 
pressure is focused to the center of the cupola which is the 
point of combustion, in other words, the four flames meet at 
one combined point, producing at least 3000 heat units through 
this space, at which point all the particles of iron being melted 
above must pa^s before reaching the bottom. The intense heat 
will remove all slag and sulphur absorbed by the iron on its 
way downward, thus obtaining combined carbon as soon as the 
globules pass through the intense heat, guaranteeing against 
the chilling of the iron and insuring a close fluid metal that 
can be worked freely. 

"We claim for the Holland Cupola the following advantages: 

1st. Any quality of coke or hard coal can be used, 
14 



2IO THE CUPOLA FURNACE. 

2d. 75 per cent, of stove scrap, 25 per cent, of No. 2 pig 
iron will give a soft close iron. 

3d. There is no trouble of the first or last iron being hard. 

4th. No such thing as hard iron, but a continuous flow of 
nice workable metal. 

5th. The acme of perfection in the melting of high and low- 
grade iron into the desired quality of casting. 

6th. We guarantee satisfaction in every respect when direc- 
tions are conformed to in the operation of our cupolas. 

7th. Hot blast without the oil is a perfect safeguard against 
the chilling of the iron. By combining the oil with the hot 
blast a more superior iron is produced, only requiring 4 gal- 
lons of crude oil to one ton of iron. By the use of oil you can 
melt with gas-house coke. By using the oil you cannot chill 
the iron by pouring it on iron plates. Tlie cupola can be 
used with or without oil." 

Note. — The writer has not seen this cupola in operation, and 
therefore can neither confirm or deny these claims. 

bailt.ot's cupolas. 

Baillot's cupola, which is classed as a hot blast cupola, is of 
French design, and uas placed on exhibition at the American 
Foundrymen's Association, Toronto, Canada, 1908, where many 
of our readers may have seen it in operation. At this time the 
hot blast was drawn from the cupola just below the charging 
door, passed through a fan-blower, and returned to the cupola 
through the tuyeres. This theory of obtaining a hot blast for 
a cupola may be something new in France, but it is not new in 
this country, and was noted in my cupola work of 1877, as 
follows : — 

Several attempts have been made to draw hot air from the 
stack of the cupola and again force it in at the tuyeres. To do 
this the supply pipe for the fan or blower has been connected 
with the stack just above the charging door, and the hot air 
drawn from the cupola and forced through the fan or blower 
into the tuyeres. This arrangement has in every instance been 



HOT-BLAST CUPOLAS. 



211 



a failure, for the hot air from the cupola soon heated the fan or 
blower and burned ofif the belt and ruined the machine. It was 
also noted more extensively in the first edition of this work in 
1899. The only difiference in these experiments and that of 
Baillot was that the heated air was taken from the stack of the 
low cupolas then in use, while in the Baillot it was taken from 
below the charging door. But the efifect of the heated air upon 

Fig. 54. 





the blower must be the same. This feature has now been 
abandoned in the Baillot cupola, and it is constructed as shown 
in the sectional views, Fig. 54, and the following are a few of 
the claims made for it by the manufacturers : 

" Our furnace is still a hot blast cupola, but we have changed 
the method of getting it. Referring to the illustration you can 



212 THE CUPOLA FURNACE. 

see, in the vertical section at the left, a ring is set in the lining 
just below charging door. That ring is connected to the blast 
chamber with a small pipe 2^^' to 6", according to size of 
cupola. That small pipe can be seen at the left of the cupola. 
The ring is also connected to the blower with a 'pipe a little 
smaller than the blast pipe. It is also visible at the right of the 
illustration. The blast pipe is connected to the blast chamber 
as usual; it is not shown on the illustration. 

" Now let us suppose the cupola in operation. The air from 
the blower will go in the blast chamber and through the tuyeres 
in the cupola. But a part of the blast will go through the 
small pipe at the left of the illustration and up to the ring. 
That ring being hot from the contact of the gases, will heat up 
the air inside. The hot air then goes back to the blower, 
where it mixes with fresh air in entering the blower. 

" The blast instead of being cold is warmed up to a tempera- 
ture of about 150^ Fahr. The results prove this is sufficient, 
as the slag does not stick to the lining, which is kept perfectly 
clean till the end of the heat, and when the bottom is dropped 
everything fall-;, there being no crown of congealed slag around 
the cupola at the elevation of the tuyeres. 

"We attribute this to the fact that the temperature of our 
blast, 150^ Fahr., is enough to evaporate most of the moisture 
of the air. which, in our mind, is the chief cause of the cooling 
of the slag around the tuyeres, and the formation of the well 
known crown inside the furnace. 

" Our previous method of taking the blast from the cupola 
was liable to hurt the blower by the action of the gases and 
cinders. But now, with the heavy cast-iron ring entirely closed 
to the inside of the cupola, the gases and cinders cannot mix 
with the blast which is kept clean and cannot injure the blower. 

" A cupola of that design runs in charge better than 14 to i. 
If we remember well at the Canada Car it was 15 to r. 

" You will see on the record that Mr. King, the Superin- 
tendent of the Canada Car, has put a note saying, that in addi- 
tion to the amount of coke mentioned, there were 40 lbs. of 



HOT-BLAST CUPOLAS. 21 3 

coke used in each operation for the crucible. That was to 
close the door of the front crucible of receiving ladle. 

"The door is not visible on the cut; it is on the side of the 
crucible, and is simply a piece of rolled steel. As it cannot be 
lined with fire brick we block it with coke taken from the drop 
of the previous heat. That is what they do now at the Canada 
Car Co. But when the tests were made, our man neglected to 
do that and used new coke which was charged against us." 

It is very difficult to see how such results as claimed for this 
cupola can be produced by heating such a small portion of the 
blast as this description indicates. But the following report of 
melting, if correct, certainly shows good results: 



214 



THE CUPOLA FURNACE. 



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CHAPTER XI. 

FREEZING THE BLAST, 

Since heating the blast for cupolas has thus far proved a 
failure, and will likely continue to be failure, owing to the 
limited time cupolas are as a rule kept in blast, the next field 
open for scientific investigation that promises any degree of 
success is freezing the blast to drive out any moisture it may 
contain. This method has been tried by blast furnace men with 
marked success in the saving of fuel, and the same results might 
be obtained in cupola practice, but we have not been able to 
learn of freezing the blast for cupolas having thus far been tried. 
There would be some difiference between this practice in fur- 
naces and that of cupolas, for in the former the blast is heated 
after having the moisture frozen out of it, which could not be 
done for the cupola. Many founders claim they obtain hotter 
iron with the same per cent, of fuel in the winter when the air 
is dried by being frozen than in summer when the air is laden 
with moisture. This being the case, a blast with the moisture 
all frozen out of it should produce a hot, fluid iron with less fuel 
than required in either summer or v\ inter. But this claim that 
hotter iron is obtained in the winter has never been proven, to 
our knowledge, by scientific investigation, and may only be due 
to the appearance of the molten iron in a ladle, which always 
appears hotter in a dark day of winter than in the warm, clear 
days of summer. The freezing of blast can readily be effected 
by passing it through a cold storage or artificial ice plant, as 
has been done by blast furnace men, and this may be tried by 
some of the larger foundry plants at an early day and a con- 
siderable saving efTected in fuel. But freezing plants are too 
expensive at the present time to be installed for freezing the 

(215) 



2l6 THE CUPOLA FURNACE. 

moisture out of the blast for a cupola that is only in blast from 
one to two hours per day in melting a few ton of iron. 

MOISTURE IN BLAST. 

While hot and dry blasts for cupolas have received consider- 
able attention, the wet or moist blast has not been forgotten. 
For while it is claimed by many founders, that hotter iron is 
melted with the same per cent, of fuel with the cold dry air of 
winter as a blast, it is also claimed by others that hotter iron 
is melted on a wet day or in a damp atmosphere than on a dry, 
clear day, and many attempts have been made to produce a 
blast containing a per cent, of moisture equal to or above that 
of a damp wet day. Probably one of the most exhaustive ex- 
periments made along this line in this country, was that of 
The Lobdel Car Wheel Co., Wilmington, Del. This company 
constructed an underground air chamber, 50 feet long and 3 
feet square, through which the blast was passed just before 
entering the cupola. At intervals of every few feet pipes were 
arranged across the whole length of this air chamber so as to 
throw a spray of water over the top and also to have the bottom 
of it covered with water. It was hoped by passing the blast 
through this chamber to add moisture to it, and obtain the hot 
fluid iron of a damp wet day with less fuel. But no reduction 
in fuel could be affected with this blast. A greater number of 
sprayers were then put in and the blast virtually forced through 
a very heavy rain storm, but this gave no better results. The 
air was then analyzed before entering the chamber, and after 
passing through it, to determine the per cent, of moisture it 
had taken up, and it was found that not one particle of moisture 
had been added to it in passing through the chamber. Steam 
was then tried in the air chamber with no better results in add- 
ing moisture to the blast, and the experiment was given up as 
a failure. These experiments were followed up in various 
ways until it was conclusively shown that moisture could not 
be added to the blast by any such device, but they failed to 
determine, whether the moist air of a wet damp day produced 



FREEZING THE BLAST. 217 

hotter iron, than that of a dry day, for no moisture was added 
to the blast. 

Water has also been sprayed into the blast at the tuyeres, 
with a view of obtaining a moist blast, but this too proved a 
failure, as no saving in fuel was effected, or a perceptible im- 
provement in the quality of iron observed. 

Steam under low and high pressure has also been forced 
into the cupola at the tuyeres, together with the blast, for the 
purpose of giving a moist blast. Great results have from time 
to time been claimed for this process for improving the quality 
and strength of the iron melted, it being asserted that iron 
melt d with this process could be punched without cracking or 
breaking the same as wrought iron. But this claim failed to 
hold good, for in all cases, the same mixture of iron that can 
be punched without cracking, obtained by blowing in steam, 
can as readily be punched without steam having been used. 

Since writing the foregoing pages on dry and moist blast the 
following articles have appeared, together with comments by 
the editor, in the January, 1910, issue of " Castings." As these 
articles answer some of the problems of the foregoing pages 
and also present some new suggestions, they are here inserted 
for the consideration of the reader. 

Wealker and the Output of the Cupola * 

Why does the cupola melt better on a cold day in the winter 
than on a hot summer day? Why does a cupola melt better 
on a rainy day in the summer than on a dry day at the same 
season of the year? These are questions that are constantly 
being asked, and have puzzled many a foundryman. Both are 
easy of answer if we consider the underlying principles. 

Air Capacity for Moisture. — As a given volume of air is 
heated at constant pressure it expands and at the same time its 
capacity for moisture is very greatly increased. In locations 
near the sea or where there are considerable bodies of water to 

* By M. H. Bancroft. 



2l8 



THE CUPOLA F"URNACE. 



draw from, air is usually fairly saturated with moisture. The 
table below gives the weight of a cubic foot of air at several 
temperatures and also the amount of water contained in the air 
at these temperatures. 

The figures given in this table correspond to a barometer 
reading of 29.921 inches of mercury, the ordinary reading at 
the sea level. If air at a relatively high temperature and satu- 
rated with moisture is suddenly cooled, the moisture will be 
precipitated as rain or dew if the temperature is above 32 
degrees Fahr., and as snow or frost if the temperature is below 
32 degrees. Air that is almost saturated seems dry to us, 
while that which is supersaturated seems moist and in the 
lower temperatures colder than it actually is. In temperatures 
that approach bloodheat, very moist air seems hotter than is 
really the case. 



EFFECT OF HEAT ON AIR. 



Temperature 
in degrees 
Fahrenheit. 


W 

I 


eight of air in 
cubic foot in 
pounds. 







.0863 


32 




.0802 


62 




.0747 


82 




.0706 


92 




.0684 



Pounds of water 
in I cubic foot. 



,000079 
.000304 
.000887 
.001667 
.002250 



Total number 

pounds of air and 

moisture. 



.086379 
.080504 
.075581 
.072267 
.070650 



Weight of Air and Amount of Entrained Water at Various Temperatures. 



Let US now investigate the efifect of the varying degree of 
moisture and also the effect of changes in the density of air due 
to variations in the temperature. Between zero and 92 degrees 
Fahr. the expansion of air as shown in the table has reduced 
the weight of a cubic foot 26 per cent, in terms of the higher 
temperature. At the same time the amount of moisture which 
air can carry has been increased 27 ^/^ times. 



FREEZING THE BLAST. 219 

Air is always supplied to a cupola by a fan or blower which, 
under given conditions and in a stated length of time, delivers 
a definite volume of air. Any change in the density of air will 
therefore affect the amount of oxygen entering the cupola and 
any alteration in the amount of water the air carries will also 
have its effect on the combustion. Whatever enters the tuyeres 
must pass through the fire. Water that goes in as an invisible 
vapor will dampen the fire just as effectively as an equal amount 
introduced from a hose. 

Load on Blower or Fan. — If we compare the combined weight 
of a cubic foot of air and the moisture it contains, we find that 
between zero and 92 degrees Fahr. there is a difference of 
.01 5662 pound per cubic foot. This is a change of 22 per cent, 
in the weight of a cubic foot of air and its contained moisture 
when compared with the weight at the higher temperature. In 
other words, at zero degrees Fahr. to pass a given number of 
cubic feet of air a fan or centrifugal blower must do 22 per 
cent, more work. These is another factor, however, which 
neutralizes this effect to a considerable extent. Owing to the 
greater density of the air the fan has a tendency to slow down 
as the load increases, and also owing to the greater density the 
amount of oxygen introduced at the lower temperature is greatly 
increased. 

In comparing the amount of moisture introduced at different 
temperatures we will consider the temperatures of 32 degrees 
and 92 degrees, the object being to eliminate the influence of 
the freezing point from our calculations. 

When a pound of water at 32 degrees Fahr. is heated, it ab- 
sorbs an amount of heat known as a British thermal unit for 
each degree's rise in temperature. To raise one pound of water 
from 32 degrees to the boiling point, 212 degrees, would re- 
quire 180 British thermal units. 

When the water reaches the boiling point it is converted into 
steam, but while this phenomenon is going on a great deal of 
heat is used up without increasing the temperature. This is 
known as the latent heat of vaporization, and represents the 



220 THE CUPOLA FURNACE. 

energy expended in changing water to steam. To change one 
pound of water from a fluid at 2 12 degrees to steam at the 
same temperature requires 965.7 British thermal units (^com- 
monly abbreviated to B.t.u.). 

Temperature of the Air. — After the moisture has been con- 
verted into steam its specific heat is .48. In other words, it 
takes .48 of a B.t.u. to make a rise in temperature of i degree 
in a pound of steam. For clearness and to save dealing with 
very small figures, we will consider the amount of moisture in 
i,oco cubic feet of air at 32 degrees Fahr. This is .304 pound, 
while at 92 degrees it is 2.25 pounds. 

The amount of heat necessary to raise the moisture in 1,000 
cubic feet of air at 32 degrees Fahr. to the temperature of the 
melting point in a cupola, which for these calculations is taken 
at 2,700 degrees Fahr., is shown by the following calculation : 

.304 X 180 = 54-72 B.t.u. required to raise the moisture 
from 32 degrees to the boiling point. 

.304 X 965.7 = 293.57 B.t.u. required to convert the moist- 
ure into steam. 

.304 X 2,488 X .48 = 363.05 B.t.u. required to raise the 
steam from 212 degrees to 2,700 degrees, or a total of 711.34 
B.t.u. 

We will next consider the amount of heat necessary to raise 
the moisture in i,coo cubic feet of air at 92 degrees to the 
melting point of iron. These calculations are as follows: 

2.25 X 120 = 270 B.t.u. required to raise the moisture to 
the boiling point. 

2.25 X 965,7 = 2,152.82 B.t.u. required to convert the 
moisture into steam. 

2.25 X 2,488 X .48 = 2,687.4 B.t.u. to heat the steam from 
the boiling point to the temperature of the melting zone in the 
cupola. 

This makes a total of 5,109.86 B.t.u. The difiference be- 
tween these two figures amounts to 4,398.52 B.t.u. 

Ratio of Air and Coke. — Most foundry coke averages about 
10 per cent, ash, or stated the other way, about 90 per cent. 



FREEZING THE BLAST. 221 

carbon. To burn this carbon would require 129.6 cubic feet 
of air at 32 degrees Fahr. In most cases, however, owing to 
the fact that some air escapes up past the charge along the 
lining and that the combustion is not uniform throughout the 
charge, a slight e.xcess of air has to be added. A 10 per cent, 
excess brings our figures up to 150 cubic feet of air to burn a 
pound of coke. It is probable that in practice somewhat more 
than this proportion is used. 

If we consider a melting ratio of 8 to i, it will require 250 
pounds of coke to melt the 2,000 pounds of iron. By multi- 
plying the weight of coke by 150, we conclude that it will take 
37.500 cubic feet of air to melt the ton of iron. 

Temperature of Moisture. — Of course if the melting ratio is 
higher, it will require less air. If it, is lower we will have to 
blow a greater amount into the cupola. If we refer to our 
former figure, which gave the B.t.u. necessary to raise the 
moisture in t.ooo cubic feet of air from 92 degrees to the tem- 
perature of the melting zone in a cupola, we see that this figure 
is 5.109.86. 

If we divide this by i, coo, to obtain the amount of heat 
necessary to raise the moisture in one pound of air to the tem- 
perature mentioned, we find that it is 5.109, or approximately 
5.1 1 B.tu. 

Waste Heat. — Multiplying this figure by 37,500, the amount 
of air required to melt one ton of iron, we ascertain that we are 
wasting 191,625 B.t.u. by having to heat the moisture which 
enters with the air. 

One i)ound of the best coke contains 14,500 B%t.u. Divid- 
ing 191,625 by 14,500, we discover that it requires over 14^ 
pounds of coke simply to take care of the moisture which is 
introduced to melt a ton of iron under ordinary summer condi- 
tions. In the winter we are introducing one- seventh as much 
moisture and it will require less than two pounds of coke to 
take care of the moisture in the air which wc introduce to melt 
a ton of iron. 

Coke ill Summer and Winter. — In other words, if we use a 



222 THE CUPOLA FURNACE. 

given weight of coke which is sufficient to melt a ton of iron in 
the summer, in the winter we have about ii pounds of coke to 
each ton of iron which is used for superheating the iron or 
which may be used for melting an excess quantity. This 1 1 
pounds of coke in the winter would be capable of melting over 
88 pounds of iron at the ratio which we have taken and would 
produce it at the same temperature that the cupola delivered 
its product in summer weather. 

The reason why a cupola works better on a rainy day in the 
summer than on a dry day, is simply that a rain cannot occur 
without a falling temperature. The falling temperature reduces 
the amount of water which a given volume of air can contain 
and thus reduces the amount of moisture entering the cupola. 
This in turn sets free some of the coke and allows it to super- 
heat the charge. 

Moist or Dry Cupola Blast* 

Many founders are of the opinion that hotter iron is melted 
on a wet, damp day when the atmosphere used as blast is laden 
with moisture than can be melted on a dry clear day with the 
same per cent, of fuel. They attribute this result to moisture 
or water in the blast. Numerous attempts have been made to 
add this moisture to the blast in drj' weather, such as passing 
it through a spray of water or steam just before entering the 
tuyeres. 

Adding Steam or Water to Blast. — These attempts have 
failed owing to the failure of the blast to absorb moisture as 
shown by analysis of the air, before and after passing through 
the spray. With the same object in view, water has been 
sprayed into the tuyeres with the blast. Steam has also been 
introduced in the same way, but without any perceptible sav- 
ing of fuel or improvement in the quality of the iron. 

Another claim made by many foundrymen is that the dry 
blast of winter, from which the moisture has been frozen, pro- 
duces a hotter iron than the moist blast of summer. I have 

* By Dr. Edward Kirk. 



FREEZING THE BLAST. 223 

never learned of any attempt having been made to freeze the 
moisture out of the air for a cupola blast, though this has been 
done with marked success, and a sufficient saving in fuel to pay 
for the installation of a freezing plant in blast-furnace practice. 
A similar saving should readily be effected in cupola practice. 

Climate ajtd Hot Iron. — It has occurred to me that these two 
directly opposite theories might readily be tried out in the 
various climates of this country and Canada without any outlay 
for plant or special devices. In the north and northwest, we 
have a temperature for several months in the year sufficiently 
low to freeze the moisture all out of the air. This is followed 
by the warm months of summer with a moist air. A careful 
test made of the amount of fuel required to melt a given 
amount of iron in the winter and then compared with that 
necessary to melt a similar heat in the summer, should readily 
determine if any less fuel is requisite with the cold dry air of 
winter, than is essential with the moist air of summer, and if 
the saving of fuel is sufficient to pay for the installation of a 
freezing plant for an ordinary-sized foundry. 

Then again, we have the wet and dry season of California 
where the moist or wet blast theory could be tested in the 
same way. A series of accurate tests might not only result in 
settling the question of which of these theories is correct, but 
also in considerable saving of fuel to the tester and a great 
benefit to the foundry industry of the country. 

Dry Air for the Cupola* 

The Gayley dry blast has become an approved and regular 
factor in the economical manufacture of iron in blast-furnace 
practice. What has been published on this subject has un- 
doubtedly set many foundrymen to considering the cupola and 
the effect of moisture upon its action. 

Elsewhere in "Castings" we publish two articles that show 
the trend of thought among our readers. One of these essays 

* Comments by the Editor of " Castings." 



2 24 THE CUPOLA FURNACE. 

is entitled " Weather and the Cupola," and is by M. H. Bancroft. 
It is a critical discussion of the subject from a simple mathe- 
matical point of view. 

The other contribution, on " Moist and Dry Cupola Blast," 
is by Dr. Edward Kirk. In this aiticle the doctor points out 
that by carrying on experiments in the wmter and then dupli- 
cating them in the summer, definite information as to the value 
of dry blast for the cupola can be obtained. 

Mr. Bancroft, however, brings out some points in his article 
which answer sundry of the queries in Dr. Kirk's essay. The 
former emphasizes the ratio of air and moisture, and shows 
that air which may seem dry is in reality (relatively) moist. 
Of course the relative humidity of certain parts of the United 
States, as for instance, southwestern and southern California, 
would have a marked effect upon this problem. In these sec- 
tions the air may be exceedingly dry during what is known as 
the dry season. This dryness is so marked that at times there 
is no dew at night even though there is a marked falling tem- 
perature. That proves conclusively that the air during the day 
contains a very small proportion of the moisture which it is 
capable of carrying. Most of the foundry plants in the United 
States, however, are located in the relatively humid eastern 
central states. 

From Mr. Bancroft's article it is evident that a considerable 
saving in fuel would be effected if a furnace could always be 
supplied with dry air. From this circumstance it would be a 
comparatively simple matter for heavy mclters to calculate the 
saving which could be effected by installing refrigerating plants 
for removing the moisture from the blast during the summer 
months. 

Dr. Kirk calls attention to the fact that air conducted through 
a spray of moisture had no more moisture after leaving the 
spray than before. Air so treated may contain less moisture, 
after passing through the spraj-, because the water cools it and 
reduces its capacity for carrying moisture. 



CHAPTER XII. 

CUPOLA FUELS. 

In these da}'s of advancement in foundry practice the sub- 
ject of cu])ola fuel is frequently referred to in several scientific 
papers, and inquiries in regard to the use of various fuels are 
frequently made, with a view of reducing the cost of fuel and 
doing more economical melting. 

Coke, when of good quality, is undoubtedly the best cupola 
fuel. With it iron may be melted rapidly and of any degree 
of heat desired for the work to be cast. It therefore possesses 
or gives the two requisites of modern foundry practice: Rapid 
melting and hot fluid iron. But all coals do not make good 
cupola coke, and foundries located nt a great distance from the 
foundry coke centers frequently find that the cost of transpor- 
tation makes their coke very expensive, and as the saying is, 
" costs its weight in gold." 

These are the founders who are looking for a cheaper and 
better cupola fuil. The latter, we fear, will be hard to find, 
but the former may be had, and a few recollections of meltnig 
done when cupola fuels were not so perfect as today and of 
experiments made with various fuels may be of interest. 

GAS AND LIQUID FUFL. 

The question is frequently asked : Why cannot iron be melted 
in a cupola for foundry work with gas, such as natural gas, 
illuminating gas; or liquid fuel, such as petroleum, oil, benzine, 
gasoline, etc., more economically than with coal or coke ? 

The reason these fuels cannot be used in a cupola is that the 
latter is constructed upon the principle of melting iron in direct 
contact with the fuel consumed in melting it. 

Iron, when first reduced from a solid to a molten state in a 
15 (225) 



226 THE CUPOLA FURNACE. 

cupola, is not sufficiently fluid to flow into a mold, and must be 
superheated and made more fluid than when first melted be- 
fore it can be used for foundry work. And a cupola fuel must 
be of a suff.cient density to support the iron when melting, and 
to superheat it to a sufficient extent before dropping to the 
bottom of the cupola to run the work to be cast. 

Gas and liquid fuel possess sufficient heat-producing units 
to melt iron in a cupola, but they are deficient in the requisite 
supporting properties of a cupola fuel. And iron, when melted 
by them, drops as soon as melted to the bottom of the cupola, 
where it cannot be sujierheated, or at least has not been super- 
heated by any plan yet devised. 

The writer, like many others, conceived the idea of melting 
iron in a cupola with these fuels many years ago, and in 1878 
laid his plars for doing so before Mr. John S. Perry and Mr. 
Andrew Dickey, of the Perry Stove Co., two of the most ad- 
vanced men in foundry practice at that time in this country. 

They thought the plan feasible, and offered me every facility 
of their foundry plant, at Sing Sing, N. Y., for melting iron 
with any of these fuels I might select. 

A small cupola was constructed with numerous small open- 
ings or tuyeres, through which a blow-pipe flame could be 
thrown upon the iron. At each of these openings a lamp filled 
wiih kerosene oil was placed, and the flame from the burner 
directed upon the iron by means of blow- pipes connected with 
a main blast-pipe supplied by a fan-blower. 

By this means it was hoped to melt iron as rapidly in a 12- 
or 18-inch cupola as it could be melted in a 60- inch cupola 
with anthracite coal. 

For the first test a bed of coal was put in up to the first row 
of tuyeres to support the iron and keep it ofT the sand bottom. 
When. the coal was well burned iron was charged, and the 
numerous blow-pipe flames were directed upon it through the 
tuyeres. The iron was rapidly melted in this test by the blow- 
pipe flames, but was not sufficiently fluid when drawn from the 
tap hole to be cast. 



CUPOLA FUELS. 22/ 

To overcome this difficulty the melting zone, which had only 
been about one foot in depth, was increased to four feet, and 
an increased number of blow-pipe flames directed upon the 
iron. This caused the iron to be melted more rapidly, but did 
not increase its temperature or make it more fluid, but rather 
decreased its fluidity ; for the rapid melting increased the body 
of molten iron passing through the bed of coal, causing it to 
pass through more rapidly, and it was not superheated by the 
bed to the same extent as when the melting was not so rapid. 

After a number of failures in this line to produce a hot iron, 
it was decided to abandon the lamps and convert the oil into 
gas with a view of getting a hotter flame. 

A retort was cast and after being properly connected with 
the cupola was charged with crude petroleum, and the flame 
from the gas generated directed upon the iron by means of the 
blow-pipe as before throughout a four-foot melting zone. 

This plan melted the iron rapidly, but like the other, failed 
to produce a hot fluid iron. 

A bed of coal was then placed in the cupola and a light 
blast put on for the purpose of superheating the iron, after 
being melted with the gas. This plan produced a hot fluid 
iron, but after superheating a limited amount of iron the bed 
became exhausted and the only way to replenish it was to 
draw off all the iron, shut off the gas and put in a new bed. 

The fresh bed had to be heated and the temperatute of the 
melting zone brought up to the melling point before melting 
could be resumed. This resulted in considerable loss of time 
and waste of fuel in melting and was not considered practicable. 

The blow-pipe theory was then abandoned and a series of 
pipes placed in the melting zone, for the purpose of super- 
heating the gas before burning it and creating a more intense 
heat than we had yet obtained. 

This plan melted the iron, but as before failed to produce a 
hot fluid iron, and the pipes in a short time became so choked 
with carbon that the gas failed to pass through them and melt- 
ing stopped. This difficulty could have been overcome to a 



228 THE CUPOLA FURNACE. 

sufficient extent to prevent the formation of carbon in them, 
but the iron melted was not satisfactory, and this plan was 
abandoned. 

After these repeated failures Mr. Perry, Mr. Dickey, and 
their entire foundry staff were consulted as to how a hot iron 
could be obtained in melting with these fuels, and a number of 
plans suggested by them were tried, all of which proved fail- 
ures. It was finally decided that a hot fluid iron could not be 
melted in a cupola with these fuels, no matter how hot the 
melting zone might be made, for the reason that the iron 
when melted dropped through the melting zone so rapidly that 
it could not be superheated. 

Since these experiments I have been called upon several 
times to assist in devising a plan to melt iron in a cupola with 
these fuels, and have learned of other experiments having been 
made, all of which proved failures. So far as I know, iron 
has never been melted in a cupola sufficiently hot and fluid for 
general foundry work with any of the gases or liquid fuels. 

Iron may be melted for foundry work with these fuels in 
furnaces especially designed for their use. 

Brass and other metals may also be melted with them in a 
properly constructed furnace for using them. 

One of the latest and most successful experimenters in design- 
ing and constructing furnaces for the melting of metals with 
oils and gases is W. J. Brown, Philadelphia, Pa , and founders 
favorably located for using such fuels may gain further infor- 
mation on the subject by addressing the J. W. Parson Co., 
Philadelphia, who are handling the furnace. 

CHARCOAL FUEL. 

The first fuel that was used in this country in smelting iron 
from its ores and also in cupola practice was charcoal, and for 
many years it was the only fuel available for these purposes. 
It produced a superior iron in many respects to that obtained 
with fuels in general use at the present time, but with the 
increase in population and disa{)pearance of the forests, char- 



CUPOLA FUELS. 229 

coal is no longer available for this purpose ; except in moun- 
tainous districts where land is worthless for any other pur[)ose 
than the growing of timber, or in thinly populated districts 
where the forests have not yet been destroyed. 

Such districts are generally located a long distance from the 
cupola fuel centers, and a few points on cupola practice with 
charcoal fuel may be of interest to foundrymcn situated in 
these localities, and also to others who are unable to get a 
satisfactory iron with other fuel. 

My experience in melting with this fuel in cupolas has been 
limited to small cupolas of from 20 to 30 inches inside diam- 
eter. But the fuel will carry as heavy a burden in a cupola as 
in a blast furnace, and is therefore available in melting in any 
sized cupola up to that of a charcoal blast furnace, which will 
include the largest cupolas now employed in the melting of iron 
for foundry work. 

When melting with charcoal the fuel and iron are placed in 
the cupola in charges, in the same manner as when melting 
with coal or coke. A sufificient quantity of shavings, straw, or 
other combustible material to ignite the fuel is first placed in 
the cupola. Upon this a layer of small, soft wood, and upon 
this a bed of charcoal extending to from iS to 20 inches above 
top of tuyeres. Upon this a charge of iron, then a charge of 
charcoal, and upon this a charge of iron, and so on until the 
entire heat to be melted is placed in the cupola. 

As charcoal is light and readily combustible, it is customary 
to fill the cupola with stock before lighting the fire, and to 
avoid wasting the fuel, to put on the blast as soon as the char- 
coal has become ignited, and there is a good fire in it at the 
tuyeres. 

Charcoal does not carry as heavy a burden as coal or coke, 
and the charges of iron are made lighter and more numerous 
than when melting with these fuels. 

The weight of charges of fuel and iron is varied to suit the 
volume of blast, which should be lighter than when meliing 
with the harder and less freely combustible fuels. 



230 THE CUPOLA FURNACE. 

The charges of fuel are made about 6 inches in depth or 
thickness, and the largest amount of iron which can be melted 
at a charge is the amount that can be melted without reducing 
the bed to such an extent that the next charge of fuel will not 
replenish the bed and bring it up to the top of the melting 
zone for melting the next charge. 

When charges of fuel and iron are properly proportioned 
iron may be melted sufficiently hot to run the lightest of cast- 
ings at a ratio of fiom 3 to 4 pounds of iron to a pound of fuel. 

It has been found in furnace practice that the best charcoals 
for fuel are made from the hard woods, and from small timber 
rather than from the large, and the second and third growth 
small, hard timber makes a charcoal that will carry a heavier 
burden and last longer than charcoal from first growth timber. 

Small cedar timber makes a very good fuel charcoal, and is 
the principal wood used for this purpose in some sections of 
the south. 

There are sections of this country where more economical 
melting can no doubt be done with charcoal than with coal or 
coke, but the results obtained when melting with charcoal are 
not to be compared to those obtained with either of the above 
fuels when fast melting and hot iron are desired. 

ANTHRACITE COAL AS A CUPOLA FUEL. 

The principal mines of this coal are located in four counties 
of eastern Pennsylvania, and the known area of the anthracite 
fields at the present time is 472 square miles, and the output of 
coal about 75,000,000 tons annually. 

Outside of these four counties in Pennsylvania there are only 
three anthracite coal mines in the United States, one in Colo- 
rado, one in New Mexico, and the third in Rhode Island. The 
aggregate output of these three mines is only about 60,000 tons 
per year, and the coal is a poor sort of anthracite. 

The Pennsylvania hard coal fields are divided locally into 
four regions, the Lehigh, the Schuylkill, the Lackawanna, and 
the Scranton. These various fields produce different grades 



CUPOLA FUELS. 23 I 

of coal. That of the Lackawanna and Scranton regions is soft 
compared with that of the Schuylkill, and that of the Schuyl- 
kill soft compared with that of the Lehigh region. 

There is also considerable difference in coal from the various 
mines in the same region. That from the deeper vems is gen- 
erally harder than that from veins nearer the surface. 

As a cupola fuel, in the days of anthracite fuel, coal from the 
Lehigh region ranked first, Schuylkill second, and that from 
the other two regions third. 

Coal from various mines in these regions also had higher 
reputations than that from others. Of all the mines Old Mine 
Lehigh had the h'ghest reputation as a cu{)ola fuel. This coal 
was of a bluish cast of color, very hard, and when placed in the 
sun in large pieces presented all the colors of the rainbow. 
Coals from other mines in this region have the same character- 
istic to a greater or less extent, but that from other regions is 
generally of a black cast of color, and the softer the coal the 
blacker it is in the fresh fracture. 

Some years ago when the largest pieces of coal that could 
be placed in a cupola were considered necessary for a good 
bed, these indicatii>ns of the qualify of a coal were considered 
of importance, as they enabled the expert foundryman to judge 
at a glance the quality of the fuel. But at the piesent time 
little or no attention is paid to ihem. 

There are no records to show when this coal was first used 
as a cupola fuel, but there are records to show that the first 
mine in the Pennsylvania districts was opened in 1810, and the 
output of coal in that year was 3C0 tons. It was probably 
about this time that the coal began to replace charcoal as a 
cupola and blast furnace fuel. 

How many years were required to introduce it for this pur- 
pose is not known, but one thing is certain, that it became the 
universal cu{)ola fuel in all the eastern sections of the country 
and as far west as it could be obtained. 

In 1875 I found it in use in many of the foundries in St. 
Louis, Chicago, Milwaukee, and various parts of Canada, and 
all the eastern section of the country. 



232 THE CUPOLA FURNACE. 

In the early days of the manufacture of coke, coal from 
almost any of the anthracite coal fields of Penns)lvania was 
considered superior to coke, but with the improvements made 
in the manufacture of coke from time to time coal has been 
comptlkd to give place to coke, until at the present time the 
use of coal as a cupola fuel is restricted almost entirely to the 
coal fields and near-by foundry districts where it can be ob- 
tained at a less cost than ccke, and to foundries a long di^tance 
from the coke centers, to which coal is delivered by vessels at a 
less cost per ton of iron melted than coke, and its use has 
become so restricted that we are compelled to write of it rather 
as a cu| ola fuel of the past than of the present. 

To illustrate the manner of charging and melting with coal 
from the different coal fields of Penns}'lvania, 1 have selected 
from my notes three heats of about the same size melted in 
different sections of the country in which these fuels were most 
commonly used. 

The first of these was melted March 25, 1876, with Lacka- 
wanna coal at the foundry of Jackson & Woodin, Berwick, Pa., 
a small town located near the Lackawanna or Wyoming coal 
fields. The iron was melted for car wheels and general car 
castings, and was not lequired to be very hot to run the work: 

Bed Coal 1900 Charge Iron 435° 

Charge Coal 5C0 " " 435° 



^co " '• 4350 

7C0 " " 435° 



Total Coal 37CO Total Iron 1 7400 

Per cent, fuel 21.2b -\-. 

Heat melted September 26, 1876, with Schuylkill coal at the 
foundry of the American Stove and Holloware Company, 
Philadelphia, Pa. The iron was used in the casting of stove 
plate and hollow ware, and required to be very hot and fluid 
to run the work : 



CUPOLA FUELS. 233 

Bed Coal 1 500 Charge Iron 4000 

Charge Coal 350 " " 4C00 



350 " " 4CC0 

350 " " 4000 

250 " " 20CO 



Total Coal 2800 Total Iron 1 8cco 

Per cent, tuel 15.55 + . 

Heat melted January 15, 1877, with Old Mine Lehigh coal 
at the foundry of the Wolf Stove Work-, Troy, N. Y. Very 

hot fluid iron for light plate was melted in this heat. 

Bed Coal 1400 Charge Iron 4000 

Charge Coal 500 " " 4000 



300 " " 4C00 

250 " " 3000 

250 " " 3100 



Total Coal 2500 Total Iron 18100 

Per cent, fuel 13.81. 

It will be observed that the weight of fuel in the first heat is 
increased each charge and the charges of iron remain the same 
throughout the entire heat, while the weight of fuel in the 
charges with the harder coal remains the satne as long as the 
weight of iron remains the same, and is decreased as the weight 
of iron decreases. 

In melting with coal it has been found that with the softer 
coals the bed gives out in a long heat, resulting in dull iron 
towards the latter end of the heat. 

To obviate this the charges of fuel are increased to keep up 
the bed and prevent iron settling too low in the melting zone 
before melting. Ihis is the mode of charging commonly fol- 
lowed when melting with soft coal. 

It will also be observed that the per cent, of coal consumed 
in melting varies to a considerable extent. This is due in 
these heats to the quality of coal. This variation always occurs 
with the difTerent coals under the most favorable conditions, 
and is due to the difference in the heat-producing units of the 
coal. 



234 THE CUPOLA FURNACE. 

The following reports from fourteen large foundries located 
in different parts of the country and using different grades of 
coal show the per cent, of coal consumed in melting for one 
year to have been 15.55, M-S f » I5-I7. 17-22, 16.12, 15.08, 15.48. 
14.70, 14.95, 18.10, 20.00, 18.72, 20.39, 19.78. 

The foundries are principally stove-plate foundries and foun- 
dries casting light work for which very hot iron is required, 
and they show the average melting done in well-regulated 
foundries of this class. 

Founders and melters who are accustomed to speaking of 
pounds of iron m.eltcd to the pound of fuel may at first glance, 
as we have known them to do, take these figures to mean 
pounds of iron melted with a pound of fuel, which is not the 
case. They represent the pounds and fraction of a pound of 
fuel consumed in melting one hundred pounds of iron. 

Prior to the dates above given every foundry appears to 
have been a mystery unto itself, and nothing was published in 
regard to cupola fuel, and it was only by promise of absolute 
secrecy as to the founder furnishing them that these figures 
were obtained. 

Prior to this date, and even at the time, it was the practice 
in many foundries to use in melting the largest pieces of coal 
they could obtain or place in the cupola. Such coal was con- 
sidered necessary to make a bed that would last through a heat 
of two or three hours. 

I have seen the largest pieces of coal a man could lift and 
place in a cupola put in for a bed, and low cupolas of frorrr 
eight to ten feet filled with wood almost to the charging door 
to ignite these large pieces of coal; smaller pieces were used 
for charging, but they were generally entirely too large for this 
purpose. 

This large coal did not make a compact fire, and large crev- 
ices or openings were left between them, through which the 
molten iron quickly dropped to the bottom of the cupola with- 
out being superheated in its descent, and it was only by using 
an excessive amount of coal that hot iron could be made. The 



CUPOLA FUELS. 235 

average melting done with this kind of fuel, when hot iron was 
required, was from three to four pounds of iron to the pound 
of fuel with the best of coal. 

Later on it was the practice in many foundries to put in a 
bed of large coal and charge with small coal ; this gave a 
better per cent, and the average melting was from four or five 
to one. 

The writer was probably the first to call foundrymen's atten- 
tion to this mi.stake in using coal, and while it is claimed by 
many that a cupola cannot be run by a book, my early work 
on cupola practice certainly revolutionized the use of coal in 
many sections of the country. 

At the time it was published many old founders and melters 
ridiculed the idea of melting with small coal, and were so posi- 
tive it could not be done that numerous bets of from one hun- 
dred to five hundred dollars were offered that it could not be 
done, and a long heat melted or hot iron made. 

But these primitive ideas of using coal soon gave way to 
better judgment when once their attention had been called to 
the matter, and the use of small coal became universal. 

Iron may be melted in a cupola with any size coal from the 
smallest to the largest if the quality of coal is good. The best 
results are obtained in either small or large heats with broken 
coal about the size of the fist or of the two fists, and no larger 
coal should be used either for large or small cupolas. 

After the adoption of broken coal for melting, the per cent, 
of coal required for making hot iron was very much reduced, 
and the average melting in well managed cupolas in large and 
small heats was from five to seven to one, and in some cases as 
high as seven and a half was obtained. This was probably the 
best ever done, although there were founders and melters who 
claimed as high as ten to one, but I have never seen any such 
melting done either in regular or test heats, and men doing 
such melting probably did it in their minds, as many do at the 
present time who melt with a very small per cent, of coke. 

When coke was first introduced into the coal melting districts 



235 



THE CUPOLA FURNACE. 



of the eastern section of the country, many founders were afraid 
to use it in their cupolas, and it was introduced by mixing it 
with coal, or by putting in a bed of coal and charging with 
coke and coal, and this practice is still kept up in many foun- 
dries where the two fuels can be obtained at the same price per 
ton of iron melted ; it being claimed that a coal bed lasts longer 
than a coke bed, and also a mixture of the two fuels in the bed 
and charges makes a hotter iron and gives life and fluidity to 
the molten iron. 

There is nothing in any of these claims, for a bed of one fuel 
will last as long as the other, and as hot, fluid and lively iron 
can be melted with one fuel as with the other, or with a mixture 
of the two fuels. 

Another claim made for the mixture of the two fuels is that 
more rapid melting can be done and larger heats melted with 
mixed fuels than with coal alone. 

There is some truth in this claim, and founders melting with 
coal can do more rapid melting and may increase the melting 
capacity of their cupolas by mixing the two fuels in the bed 
and charges or in the charges alone, or by putting in a bed of 
coal and charging with coke. 

The following heats melted with mixed fuels will illustrate 
the manner of charging and melting with the two fuels: 

Heat melted in a 48-inch Colliau cupola with No. 6 Baker 
blower, tuyeres 18 inches above the bottom, Schuylkill coal 
and Connellsville coke used in melting. Iron melted for gen- 
eral machine castings. 



Bed 


Coke 


Bed 


Coal 


Bed 


Iron 


" 


1200 


« 


600 


>( 


4000 


Charge 


250 


Charge 


100 


Charge 


4000 


" 


250 


(( 


100 




4000 


« 


250 


« 


100 




4000 


" 


250 


(( 


ICO 




4CC0 


" 


250 


M 


ICO 




4000 


" 


250 


" 


ICO 




4000 


" 


250 


" 


100 




4000 


'* 


250 


Total, 


100 


Total, 


4000 


Total, 


3200 


1400 


36000 



Fer cent, coke -; 88 4 



Per cent, cnni 8.88 



Per cent, fuel 12.77. 



CUPOLA FUELS. 



23/ 



Heat melted in 54-inch Whiting cnpola with No. 6 Baker 
blower, tuyeres 18 inches above bottom, Schuylkill coal and 
Connellsville coke used in melting. Iron melted for light mal- 
leables and required to be very hot. 



B< 


*d Coal 


Bed 


Coke 


Bed 


Iron 




' 2800 


« 


eo 


" 


3-'00 


Cha 


rge I qo 


Charge 


60 


Charge 


19CO 




150 




50 






1900 




150 




5° 






1900 




150 




50 




« 


1900 




150 




50 






19CO 




150 




50 






19CO 




150 




50 






1900 




150 




50 


( 




1900 




150 




50 






1900 




150 


" 


50 






1900 




150 




50 






19CO 




150 




50 






1900 




150 




50 






19CO 




150 


Total, 


50 






1900 


To 


tal, 4900 


770 


Total, 


298CO 



Per cent, fuel 19.02. Per cent, coke 2 58. Per cent, coal 16.44. 

In the first heat, the per cent, of coke predominates and was 
employed to do f.ist melting. The coal was used to give more 
body to the fuel and make hotter iron. In this case, the coke 
in the bed and charges was put in first and the coal on top of 
it. In the second heat, the per cent, of coal predominates, it 
being the cheaper fuel in this instance, and the small per cent, 
of coke was employed to make the cupola work more open 
and free. 

In this case, the coke was put in on top of the coal, as is 
generally done when coke is used for this purpose. 

The two fuels are also used in various other ways. In some 
foundries a bed is put in entirely of coal and charging done 
with coke alone, in others the bed is made of equal parts of 
coal and coke and the charges of the same proportions. In 
such cases it is the practice to put in the coke first and the 
coal on top. 

Coal, unlike coke, is useless as a fuel after it has been sub- 



238 THE CUPOLA FURNACE. 

jected to the intense heat of a cupola and cooled again, 
although the coal when broken appears to be as good in the 
center as before heating. I do not know of any analysis 
having been made to determine the cause of this; but it has 
been demon^trated that it cannot be burned alone in a core 
oven furnace or in a heating stove, and when mixed with fresh 
coal tends to deaden the fire and decrease the heat rather than 
increase it; and when placed in the cupola with fresh coal 
probably produces no heat. It does not pay to recover such 
coal from the cupola dump for healing purposes. 

CUPOLA COKE. 

From a paper entitled "A History of Connellsville Coke," 
prepared by Mr. F. C. Kieghley, and read before the Central 
Mining Institute of Western Pennsylvania, it appears that coke 
was first made in this country in 181 7 at Plumsack, Fayette 
County, Pa , for rolling-mill use. 

In 1837 F. H. Oliphant made coke at his Fairchance Fur- 
nace, near Uniontown, Pa. All the early coke was made on 
the ground, in what was known as coke rickets. 

The first coke made in ovens was in about 1841. In that 
year Province McCormick and James Campbell, two carpen- 
ters, and John Taylor, a stone mason, commenced making 
coke with two ovens, and in the spring of 1842 had enough 
coke stacked to fill two boats, or about 800 bushels, which 
they took down the river on a high stage of water to Cincin- 
nati, Ohio. 

This appears to have been the first shipment of coke as an 
article of commerce of which there is any record. A part of 
this cargo was afterwards boated by canal to Dayton, Ohio, 
and was there sold to Judge Gebhard, a former resident of 
Pennsylvania, who then had a foundry in operation at Dayton. 
He used the coke in his establishment and found it so well 
adapted for his purpose that he afterwards came to Connells- 
ville and proposed to Campbell and McCormick to make more. 

This appears to be the first record of Connellsville coke hav- 



CUPOLA FUELS. 239 

ing been used in a foundry, for in a long research I have been 
unable to find any record of it having been used prior to this 
date; but it is likely that coke was used in foundries prior to 
this date. For in the early days it was the custom of foundiy- 
men to make their own coke, and this practice was still in 
vogue in the sixties; and as late as 1863 the coke ovens of 
the A. Bradley Stove Works of Pittsburg, Pa., were still stand- 
ing in the foundry yards, although they were not in use at that 
time. At a still later date we have seen foundrymen making 
their own coke at a distance from Pittsburg, and it was not 
until late in the sixties that it became the general practice of 
foundrymen to buy their coke, even in the vicinity of Pittsburg. 

It was the practice for two or more foundries in these days 
to build a coke oven together, and either make their coke to- 
gether or take turns using the ovens. I remember when a boy 
going to school, one of these ovens built at Sharon, Pa., by 
William McGilvery & Co., and Joseph King & Co. It was 
located in Pine Hollow, near the Jennie Berg Hill, alongside of 
a tram road, constructed to carry coal from the mines for ship- 
ment by the canal, and was only in operation occasionally, 
when a supply of coke was required by either foundry. 

When in operation in the winter the boys always went to 
this hill to coast and get warmed at the coke oven, and many 
times have I warmed my shins at the old coke oven, when a 
boy. Later on, when a moulder in the employ of Joseph 
King & Co., I learned the history of the oven, which was re- 
moved in 1867, after having been abandoned for a number of 
years, when the supply of coke was received from Pittsburg 
and known as Pittsburg coke, made from Pittsburg coal. At 
that time there were numerous coke ovens along the Monon- 
gahela River and Allegheny Valley Railroad, employed in 
manufacturing foundry coke, which was known as Pittsburg 
coke. Later on, Connellsville coke came upon the market, 
and about 1870 or '71 completely replaced the Pittsburg coke 
as a foundry fuel. 

In these various cokes may be traced the advancement made 



240 THE CUPOLA FURNACE. 

in the manufacture of coke. That made at Sharon was a soft, 
dark coke, weighing about 32 pounds to the bushel. Pittsburg 
coke was a denser coke of a dark color, weighing 46 pounds to 
the bushel. Connellsville coke was of a light color, and when 
put upt)n the market in its early days, weighed 46 pounds to 
the bushel. The manufacture of this coke has been improved 
until we now have it of a silvery white, weighing as high as 72 
pounds to the bushel. 

Another coke that had a high reputation in early days was 
Blossburg coke, made at Blossburg, Pa. The supply of this 
coke was limited and it never came into general use, and I do 
not remember ever havmg used it in m.elnng. Numerous other 
foundry cokes have been put upon the market at various times, 
but they have, so far as 1 have been able to learn, proven 
f.iilures to a greater or lesser extent. Among these were 
Hocking Valley coke and othei;s made from Ohio coal. 

The cause of failure was due to the large per cent, of sulphur 
in the coal, which was not removed in the process of coking 
and could not be removed by various plans tried for washing 
the coal and preparing it before coking, or by devices in the 
construction of ovens for its removal. 

When engaged in the foundr)' business in Ohio in 187 1 a 
coke oven was constructed at Urichsville, Ohio, and I was 
given a half-carload of this coke to try it. The coke had the 
appearance of being a good foundry coke, but when tried in 
the cupola hardened the iron to such an ex:ent that the 
casting was worthless, and after a number of attempts to use it 
by changing the mixture of iron it was condemned. Other 
founders who were induced to try it had about the same ex- 
perience with it, and when passing the oven a few years later 
1 found it abandoned and a complete wreck. 

No coal has yet been found in this country equal to the coal 
of the Connellsville coal region for the manufacture of coke. 
This region has become the great manufacturing coke center 
of this country and the output has increased from that of a few 
ovens to thousands, amounting to millions of tons of coke 



CUPOLA. FUELS. 24 I 

annually, and probably ninety per cent, of all the foundry coke 
used in this country at the present lime is Connells\ille. It 
carries a heavier burden in a cupola and melis iron more 
rapidly than any other coke. It is said to be freer from im- 
pu'ities detrmiental to iron than other cokes, and is the mc^st 
economical fuel for the cupola, although the cost of transporta- 
tion niay render it expensive. 

When this is the case the question of economy when melting 
must be con^idcred by the founder, and I shall endeavor to 
give a few points on this subject. 

That a coke should be a good cupola coke, it is not neces- 
sary that it sliould in every respect be equal to ConneIls\iIle. 
A coke that is worthless in a blast furnace producing yco tons 
of iron a day and kept in blast for many months, or as long as 
the furnace lining will last, may be a good coke in the cupola 
mehing a few tons of iron and only in blast for from one to two 
or three hours. 

A soft coke, free from impurities detrimentnl to iron, may 
be more economical than a hard one, even if double the quan- 
tity is required to do the melting and more time is consumed 
in melting. 

Gas-house coke may be used for melting small heats and 
coke made in the vicinity f*)r other purposes may be used for 
melting if the cupola is managed to suit the coke, or founders 
may find it more economical to construct ovens and make their 
own coke from coal in the immediate vicinity, as did foundry- 
men years ago, than to pay for transporting the be;ter grades 
hmg distances. Almost any coke will produce hot iron in a 
cupola if properly managed. 

Two things are necessary in the manufacture of a good 
foundry coke. First, a good coking coal free from sulphur 
and other impurities detrimental to iron. Second, a properly 
constructed oven and a knowledge of the process of coking. 

Foundries located at a long distance from the coke centers, 
that contem|)late making their own coke with a view of reduc- 
ing cost in melting, should bear these facts in mind, and have 

ID 



242 THE CUPOLA FURNACE. 

the available coal analyzed or thoroughly tested by coking in 
a small way, before going to the expense of constructing an 
oven or ovens of sufficient capacity to supply their wants. 

In the early days of melting with coke it was the custom in 
filling a cupola, after putting in the bed, to mix the iron and 
fuel by putting in a shovel or two of coke and a few pieces of 
pig or a few shovels of scrap, and so on, until the entire amount 
of iron to be melted was placed in the cupola. 

Cupolas were filled in this way upon the theory or supposi- 
tion that iron was melted in a cupola all the way up to the 
charging door, and two or three sets of tuyeres were placed in 
cupolas, one above the other, that the tuyere pipes might be 
raised to a higher set of tuyeres and the lower ones closed, 
when it was desired to collect molten iron for a large casting. 

This practice was still in vogue in some sections in the early 
seventies, but had been abandoned long before that time in 
other sections ; and the practice of placing fuel and iron in 
charges as at the present time, adopted upon the theory that 
iron is only melted in a cupola in a given space, which has 
been designated the melting zone. 

With the system of mixing the iron and fuel the per cent, of 
fuel consumed was much larger than with the present system, 
and the melting slower. When visiting foundries where this 
system was in use, I have frequently reduced the fuel consumed 
one-half and the time required for melting an equal amount, 
by changing the manner of filling the cupola to the charge 
system. 

In early days, coke was all measured, bought and sold by 
the bushel, instead of by weight, and after the adoption of the 
charge system bushel baskets were used for measuring the 
coke and placing it in the cupola. A founder when speak- 
ing of the ratio of fuel to iron melted, would state the amount 
melted per bushel of coke, in place of to the pounds of coke. 

The bed and charges of coke were placed in the cupola by 
measure instead of by weight. To learn the number of bushels 
of coke required for a bed for a cupola of any given diameter, 



CUPOLA FUELS. 243 

the number of cubic inches in the space to be filled was ascer- 
tained, and this number divided by the number of cubic inches 
m a bushel. 

For example, we will take a 30-inch cupola, with tuyeres 6 
inches in diameter located 12 inches above the sand bottom. 
This would make 18 inches from bottom to top of tuyeres. 
Add to this 18 inches for bed above top of tuyeres and we have 
a space or depth to be filled of ^6 inches. The area of 30 
inches diameter is 707 ; multiply this by 36 and we find the 
area to be filled to be 25.452 cubic inches. Divide this num- 
ber of cubic inches by the number of cubic inches in the 
average bushel, 2,200, and we find 1 1^ bushels of coke would 
be required for a bed for this cupola. 

The charges of coke were generally made 5 inches in thick- 
ness, and the amount of coke required learned by multiplying 
707 by 5 and dividing the product by 2,200, which gives the 
amount of coke required for each charge, 1.6 bushels. 

To these bushels were added, from time to time, a sufficient 
amount to make up for the burning-away of the lining and en- 
larged diameter of the cupola. 

The melting qualities of a coke were judged by its weight 
per bushel. A soft, porous coke weighed 32 pounds and the 
harder and better the coke the heavier it weighed up to 46 
pounds per bushel, which was regarded as the maximum 
weight of the best coke. The weight of a charge of iron on 
the bed varied with the quality of coke, and was from an equal 
weight of the bed to three times its weight. And the amount 
of 'iron placed in each charge varied from two to ten times the 
weight of the coke placed in the charge to melt it. 

The number of pounds of iron melted to pounds of fuel 
varied with quality of coke and size of heat, and was from 3 to 
8 to I. This was the common practice of judging the quality 
of coke and melting in all the leading foundries in the early 
sixties. And in many of them there was more system in melt- 
ing than in one- half the foundries at the present time. 

In the early days of coke its quality varied to a considerable 



2 44 THE CUPOLA FURNACE. 

extent. This was due to the differences in the coal from which 
the coke was made, and again to badly designed and poorly 
constructed ovens and to lack of knowledge of the process of 
coking. 

The-e -difficulties have been overcome by the discovery of 
veins of coal more suitable for coking, the construction of 
ovens better adapted for the purpose, and a more perfect 
knowledge of the process of coking. Coke at the present time 
is of a more uniform grade than years ago, but there is still a 
considerable difference in the characteristics of the various 
kinds. 

This variation is due in some instances to the quality of coal,, 
but more frequently, especially in coke of the Connellsville 
region, to the time consumed in coking. This region has pro- 
duced from time to time 24, 36, 48 and 72-hour coke. These 
cokes differ in density or hardness, according to the time con- 
sumed in coking, and vary in weight from 40 .pounds to 72 
pounds per bushel, which latter is said to be the weight of the 
Davis by-product coke. 

The greater the length of time coke remains (up to a certain 
period ) in an oven in the process of coking, the denser and 
harder it becomes. And the harder a coke, the longer time re- 
quired to consume it in a cupola, the heavier the burden it will 
carry and the larger the amount of iron it will melt. 

It therefore follows that a 72 hour coke is the best cupola 
coke; next to this is the 48 liour coke, and so on down to the 
24-hour coke. 

Seventy- two hour coke for many years, and if we are not 
mistaken, at the present time, is only made once a week in the 
Connellsville region. The coke men of this region follow the 
example of the Lord, as set forth in the Bible, "And on the 
Seventh day rest from all their labors," and no ovens are 
drawn on Sunday. The coke in ovens falling due to be drawn 
on Sunday as 48-hour coke, is permitted to remain in the ovens 
until M.)nday, when it becomes ; 2-hour coke, and this is the 
only 7J-hour coke made. It is generally kept for filling 



CUPOLA FUELS. 245 

foundry orders, but the supply is limited, and when exhausted 
orders are sometimes filled with 48-hour coke instead of 72- 
hour. 

This is one of the reasons for the variation in the quality of 
foundry cokes and the cause of bad workings of cupolas and 
poor melting, for the different grades of coke require a varia- 
tion in the charging of a cupola, when coke is charged by 
weight in place of by measure. 

The cupola furnace is a space furnace in which iron is melted 
in direct contact with the fuel, and is supported by the fuel 
previous to melting. 

To melt iron in this furnace, a sufficient space must be filled 
with fuel to admit of the iron to be melted entering the melting 
zone when the cupola is in blast as rapidly as it can be tnelted. 

If the amount of fuel is insufficient to fill the cupola to a 
proper height, the iron placed upon it settles below the melt- 
ing zone and cannot be melted ; and if the fuel is in excess and 
fills the cupola above a proper height, iron placed upon it can- 
not be melted until the excess of fuel is burned away, and per- 
mits the iron to settle into the melting zone. 

It is therefore a matter of space occupied or filled by fuel 
rather than of weight of fuel. With the old rule of placing 
coke in a cupola by the bushel, all cokes filled the same space, 
no matter to what extent their weights might differ per bushel. 
But the same weights of the different cokes do not fill the same 
space. 

To illustrate this we will take the cupola above referred to, 
for which 1 1.56 bushels of coke are required for a bed. This 
number of bushels of coke of the various weights per bushel 
gives the following total weights : 

Coke 32 lbs. per bushel 369 92 

Coke 46 lbs. per bushel 53' -76 

Coke 60 lbs. per bushel 693.60 

Coke 70 lbs. per bushel 809.20 

The total weights of any of these cokes would make a bed 



240 THE CUPOLA FURNACE. 

for this cupola, but the same weight of no two of them would 
make a proper bed. 

For instance, were we to put in the weight of 11.56 bushels 
of 32-pound coke, 369.92 of 70-pound coke, this amount would 
not fill the cupola to the top of tuyeres, and not a pound of 
iron could be melted with such a bed. 

On the other hand, were we to put in the weight of 11.56 
bushels of 70 pound coke, 809-20 of 32-pound coke, the cupola 
would be filled to such a height above the tuyeres that not a 
pound of iron could be melted until 439.28 lbs. of coke was 
burned away and permitted the iron to settle into the melting 
zone. 

The same rule applies to the charges equally as well as to 
the bed, and when the space between the charges of iron occu- 
pied by fuel is too small, the bed is not properly replenished, 
and the result is dull iron after one or more charges have been 
melted. 

When the space filled with fuel is in excess, irregular and 
slow melting results, due to the melting being stopped while 
the excess of fuel is being burned away to admit of the next 
charge of iron settling into the melting zone. 

Melters who do not understand the space theory of a cupola 
will invariably increase the weight of coke in bed and charges 
when they have a soft, light coke to melt with, and decrease it 
when they have a hard, heavy coke. This is a mistake, and 
exactly the reverse should be done. For the lighter a coke, 
the more space it occupies, and the heavier a coke, the less 
space it occupies, as illustrated in the bed of 32-pound and 
70 pound coke. And by increasing the weight of coke, or 
even putting in the same weight with a light coke as a heavy 
one, too great a space is filled with fuel, and iron is placed too 
high in a cupola for either fast or economical melting. 

This theory of melting should be followed by every founder 
melting with coke, and as the quality of the different cars of 
coke frequently varies to a considerable extent, some means 
should be devised or provided in every foundry for determin- 



CUPOLA FUELS. 247 

ing the weight of coke per cubic foot or bushel when such 
information is not furnished with the coke, and charging should 
be made to suit the quality of the coke. 

Hot iron may be melted in a cupola with any grade of coke 
if this theory of melting is practiced ; and equally hot fluid iron 
can be melted with a 32-pound as with a 70-pound coke. 

But it must be remembered that a light coke is inferior to a 
heavy one as a cupola fuel. It will not carry as heavy a bur- 
den or melt iron as rapidly, and a cupola cannot be kept in 
blast in good condition for melting for so great a length of 
time. And with a very light coke, it is sometimes necessary 
to make the size of a heat to suit the coke, for even by tapping 
slag a cupola could not be kept in blast for any great length of 
time with light gas-works coke, while a cupola may be kept in 
blast as long as the lining will last with a good quality of coke, 
and good melting done throughout the heat. 

The remedy in melting when coke is poor is not to increase 
the coke, but to decrease the weight of iron on bed and charges, 
and they should be varied to suit the coke. When a coke is 
light, and the weight placed in the bed and charges is reduced, 
the weight of iron placed upon them should be correspondingly 
reduced ; and when coke is heavy, the weight in bed and 
charges should be increased and the weight of iron also 
increased. 

Coke and iron should be evenly charged throughout a heat, 
that is, the proportion of fuel to iron should be the same. 

The old rule of charging is to place three pounds of iron to 
one of coke in the bed, upon the bed, and ten to one upon the 
charges. 

This rule is a good one, as it gives the proportion of fuel to 
iron throughout a heat, and with 46-pound coke and tuyeres of 
a certain height gives about the proper proportion of fuel to 
iron for fast and economical melting. But the rule is not appli- 
cable in all cases. In the first place, the rule does not apply 
to cupolas with tuyeres of different heights, for fuel under the 
tuyeres takes no part in melting, and when tuyeres are very 



248 THE CUPOLA FURNACE, 

high the amount of coke required for a bed is so large that 
three to one cannot be melted upon it without lowering ihe top 
of the bed to such an ext«. nt that it is not restored to a proper 
height for milling by the next charge of fuel. The result is 
uneven melting and dull iron throughout the remainder of the 
heat. 

With low tuyeres the weight of coke required for a bed is 
not so great, and four or five to one may be melted upon it 
with the same grade of coke without detriment to further 
melting. 

Again, the rule does not apply accurately to coke of difTerent 
grades; for we have found in a number of case>, when meltirg 
vi^ith gas-wcuks coke, that from one to two to one was the best 
that could be done on the bed, and from five to six to one the 
be'-t that could be done on the charges ; and in tlie same cupola 
we have melted four to one on the bed and ten to one on the 
charges wiih a good coke. 

In regulating melting in dififerent foundries we have found 
our best guide for bed and charges to be measurement and 
weight, as follows : 

When melting in a cupola we had never seen melt, and for 
which previous melting was no guide for melting, we first ob- 
tained the measurement from sand bottom to top of tuyeres, 
then measurement from bottom of charging door down to a 
proper height for top of bed, and procured a pole or rod for 
determining this measurement when the bed was in. We then 
determined the quality of coke by weighing a bushel, or by in- 
spection. The blast machinery and pipes were then inspected 
and a bed put in to suit the coke and blast. With a light coke 
the bed was made a iittle higher than with a heavy one. And 
with a strong blast it was made higher than with a light blast, 
the height of bed generally being from 18 to 20 inches above 
top of tuyeres. 

When the tuyeres were very high, 18 to 20 inches above 
sand bottom, and the coke light, one to two pounds of iron 
were placed upon the bed to every pound of coke in the bed. 



CUPOLA FUELS. • 249 

And with a heavy coke two to three to one were placed on the 
bed. 

With low tuyeres, four to eight inches above sand bottom, 
and light coki, two to three to one; heavy coke, three to four 
to one. The top of bed and also charges of fuel and iron were 
made as level as possible before putting in the next charge. 
For charges of coke, a sufficient quantity was put in to properly 
cover the iron (about five or six inches), and separate charges 
of iron. 

On the charges of coke were placed from three to five of iron 
to one wiih a light coke, and eight to ten to one with a heavy 
coke. 

This means of determining the proper amount of fuel for bed 
and charges and ratio of iron on fuel, in bed and charges, sel- 
dom failed to produce satisfactory melting, which might or 
might not be improved. 

To determine this the melting was watched from the time 
the bhist was put on until the bottom was dropped for indica- 
tions of necessary changes. All coke and iron was accurately 
weighed, the front put in and tuyeres closed as soon as bed 
was properly burned for charging, and charging began fiom 
two to three hours before blast was put on. 

If iron ftiiled to appear at the tap hole in five minutes after 
the blast was on, the bed was too high, and for the next heat 
was reduced a little. If iron came dull at the latter end of 
charges, charges of iron were too heavy and were reduced next 
heat. 

If the cupola did not melt rapidly the charges of fuel were 
too heavy. If iron was not of an even temperature through- 
out a ht at charges of fuel and iron were not of a proper pro- 
portion. 

All these things were noticed and changes made in the 
charging until the cupola melted the largest stream of iron it 
was capable of mehing suitable for the work to be cast, and an 
even temperature throughout a heat. 

When this had been acconiplished, the most economical 



250 THE CUPOLA FURNACE. 

melting that could be done in that cupola with the grade of 
coke used was being done, and it did not matter whether two 
to one or ten to one was being melted, the per cent, of fuel to 
iron could not be reduced. 

The question of per cent, of coke to iron or of the number of 
pounds of iron that can be melted to the pound of Connells- 
ville coke is a matter upon which there appears to be a wide 
difTerence of opinion, and upon which few are capable or will- 
ing to give definite practical information. 

Periodically there appears in the scientific and mechanical 
papers a good cupola record, in which the writer claims to 
have melted anywhere from 10 to 15 to one. 

In Mr. West's work, " The Holder's Text Book," we find re- 
ports of melting with Connellsville coke from 24 foundries, in 
which the per cent, of fuel to iron of no two of them is the 
same and the ratio of fuel varies from StVo to i 1y\ to one. 

In these reports the size of heats varies to a considerable ex- 
tent, but the largest heats do not always show the lowest per 
cent, of fuel to iron, and we find heats of 8,000, 10 to one; 
41,000, 7.84 to one; 21,000, 5.91 to one; 3,500. 6.64 to one; 
and in very few of them do the largest heats show the best per 
cent, of iron to fuel, which would seem to indicate that the old 
theory, that the larger the heat the smaller the per cent, of 
fuel, was all wrong. 

These reports indicate that the management of cupolas is 
very poorly understood by the majority of the foundrymen 
making them, or that others through a desire to excel have 
misrepresented their meltings ; and we are inclined to believe 
the latter to be the case, for in all our experience in melting we 
have never seen any such melting done as reported by some of 
them ; nor have we ever niet a practical founder who made 
such extravagant claims. 

Few practical founders claim to melt more than eight to one 
in their largest heats, and the majority of them do not state 
their average melting to be more than seven to one, and many 
place it even lower with the best of coke. 



CUPOLA FUELS. 25 I 

As stated above, the best and only guide the founder has to 
economy in fuel is fast melting and iron of a temperature suit- 
able for work to be cast; and when he melts his iron as fast as 
a cupola is capable of melting and of a temperature at the 
spout suitable for the work, he is doing all that can be done to 
save fuel, and no attention should be given to extravagant 
cupola reports made by other foundries. 

BY-PRODUCT COKE. 

Within the past few years a marked advance has been made 
in the manufacture of by-product coke, and it has taken its 
place as a cupola fuel to the extent of excluding Connellsville 
and other cokes in many localities. At Syracuse and Roches- 
ter, N. Y., what is known as the Solvay coke made at the Sol- 
vay plant, Syracuse, N. Y., is about the only coke used for 
melting in the foundries of these cities. This company also 
have works at Milwaukee, Wisconsin, which supplies a very 
large per cent, of the cupola coke used in that city, and also at 
Chicago and other places where their coke is in great demand. 

The Illinois Steel Co., Joliet, 111., and other large plants in 
the west have erected by-product coke plants for making their 
own coke from western coal, and it would appear to be only a 
question of a very few years when the West will be making all 
their own foundry coke from western coal. Owing to the large 
per cent, of sulphur this coal contains, it was not thought pos- 
sible, a few years ago, to make a good foundry coke from it, 
but a new process has been found that so thoroughly eliminates 
this element from the coke, that it is said to be more free from 
it than many of the Connellsville cokes. 

By-product coke is darker in color, is not produced in so 
large pieces, and has not the luster or ring of Connellsville 
coke, but it is said to possess an equal number of heat-produc- 
ing units, and in cupola practice gives equally as hot and fluid 
an iron. 

There appears to be considerable difiference in the density of 
by-product coke made by dififerent processes, and some carry 



2 52 THE CUrOLA FURNACE. 

a much heavier burden in melting than others. For this reason 
charges of iron have sometimes to be. made lighter than with 
ConntlLsville coke. But with the Solvay coke charges are 
made about the same and results in n)elting per pound of coke 
are about the same, although in some cases it is claimed better 
re.'^uhs have been obtained by the use of it than with Connells- 
ville. 

BITUMINOUS COAL AS A CUP. )LA FUEL. 

Between the period of the discovery of bituminous coal in 
this country and the introduction of the process of coking, there 
should have been, and no doubt was, a period when this coal 
was employed as a cujiola fuel by some of the many small 
foundries located in the vicinity of these mines. 

But there appears to have been no record kept of this coal 
as a cupola fuel by any of the foundrymen of those da)'S, or 
nothing published in regaid to it ever having been used for 
this purpose. That there should be no such records is not 
strange, for nothing can be found upon the subject of any of 
the other cupola iucU, or mode of using them, piior to my 
work, "The Founding of Metals" (1877). Nor does there 
appear to have been anything published upon this subject, in 
England or other countries prior to that date. 

Twenty-five years ago I made inquiry among foundrymen 
and molders in different parts of the country as to the use of 
various cupola fuels in their early days. Many of them re- 
membered melting with charcoal before the introduction of 
anthracite coal and coke in their locality, but only three, my 
notes show, remembered melting with bituminous coal. 

Two of these were located in Western Pennsylvania and one 
in Ohio when melting was done with this coal without coking, 
but none of them had kept any record of the melting and were 
unable to give any practical data in regard to melting with it. 

My own experience in melting with this fuel in a cupola has 
been limited to one cupola, that of Joseph King & Co., Sharon, 
Pa. 

This firm received their supply of cupola coke at that time 



CUFOLA FUELS. • 253 

from Pittsburg, Pa., by boat, on the Erie and Pittsburg Canal ; 
and it was their custom to l.iy in a sufficient supply in the fall 
to last until the canal opened in the sprinfjj. 

In the winter of 1865 and 1866 their supply ran short, and 
they were compelled to pay the high rate of a railroad that had 
just been opened the year before, look for other fuel, or shut 
down until the canal opened. 

At that time the Sharon Iron Co. were using a very hard 
bituminous coal in their bl.ist furnace without coking, and the 
foundry company were induced to try this coal in their cupolas. 

The first heat with it was not a success. The iron melted 
hot and dull, fast and slow, and the greater part of it was so 
dull it had to be poured in the pig bed. But part of it, in 
different parts of the heat, was sufKiciently hot and fluid to run 
light v\ork. This indicated that the fuel would do the melting, 
but the cupola had not been properly charged. 

For the next few heats the charges of fuel and iron were 
varied with better results, and in the third or fourth heats iron 
was melted sufficiently hot and fluid to run stove-plate and 
light jt/bbing work; and melting was done with this coal for a 
number of weeks, until the canal opened and they received a 
supply of coke. 

This melting was done in a 28-inch cupola. 

A bed was put in of the same height above the tuyeres, and 
the charges of coal made of same weight as when melting 
with coke. But the charijes of iron on the bed and those on 
the charges of fuel were made hghter, and the ratio of iron to 
fuel reduced from 7 to i with coke to 5 to I with coal. 

This is as good a per cent, of fuel to iron as the majority of 
founders melting small heats in small cupolas obtain with the 
best of coke. 

The quality of iron was not deteriorated by the coal, and it 
was not found necessary to make any change in the mixture to 
obtain as good a quality of iron in the castings as when melt- 
ing with Pittsburg coke. 

The coal used in this instance was very hard bituminous coal^ 



2 54 THE CUPOLA FURNACE. 

and was said to be the only coal mined in this section that 
could be used in a blast furnace without coking, which was 
probably the case, for when the mine became exhausted the 
furnace began using coke as a fuel. 

All bituminous coals are not available as a cupola fuel. Some 
are too soft, fuse into a solid mass, or burn away too rapidly 
when subjected to a strong blast, and others contain so large 
an amount of sulphur that they harden the iron and render it 
brittle. 

In selecting a coal, a hard coal free from sulphur should be 
chosen. When such a coal is not obtainable, small heats may 
be melted with a soft coal and a light blast, and sulphurous 
coals may be used for some lines of work by charging a better 
grade of iron than when melting with a fuel free from sulphur. 

There are some sections of this country in which very hard 
bituminous coal is mined, that can no doubt be employed as 
a cupola fuel by small jobbing foundries located in districts 
where other fuels are very expensive. 

A WONDERFUL CUPOLA. 

Herbert M. Ramp, Springfield, Mo., writes on this subject to 
the "American Machinist," as follows: 

" Under the above heading an article appeared in the 
'American Machinist,' September 27th, showing a cupola sup- 
posed to be doing phenomenal work, but upon a careful con- 
sideration and comparison with other cupolas on the same basis 
a great deal of the wonderful disappears. The economy is not 
as great as supposed at a casual reading. 

" In the first place the ratio of fuel to iron is given on the 
basis of what is used between charges, leaving the bed out en- 
tirely, neglecting the fact that the bed is a most important factor 
in raising the temperature of the cupola and all it contains. At 
the same time the first charge of iron is melted on the bed, and 
is clear gain in ratio of fuel on this basis. No charge being 
made against it, a considerable alteration is made in the pio- 
portion, especially if the heats only run from one to two hours. 



CUPOLA FUELS. 255 

" From my own experience I can assert that, based on the 
preceding basis, I have accomplished an equal result with that 
shown by Mr. Bollinckx. 

" The past month I have used a cupola built on the plan 
shown in the ' American Machinist,' September 20th, 30 inches 
in diameter clear of the brick. Aside from the bed I have used 
fuel at the rate of i to 20, taking the coke and iron relative in 
each charge, but upon the addition of the charge melted on the 
bed the ratio will run up to i to 22 and i to 23 ; but taking the 
same heats and adding in the fuel used on the bed the ratio is 
brought down to the more rational figures of i to 14. 

" I can safely say I have not reached the limit of this cupola, 
but my experiments have been delayed on account of several 
cars of poor coke. I had not intended to write of this cupola 
at present, and later on will present a paper on it, but American 
pride bade me proclaim what is done in our country when its 
reputation for excellence is at stake. The iron used was from 
30 to 50 per cent, pig iron, and the remainder heavy railroad 
scrap. 

" The cupola melts from 4)^ to 5 tons per hour. I make no 
claims as to the economy of the cupola, but rather to the 
management. 

"As in the case of the Greiner, there is no flame shown at 
the chargmg door, and very little gas or smoke, the tempera- 
ture at that point not running over 125° Fahr., but this is not 
due to the construction of the same, but the manner af charg- 
ing, and any cupola can be handled so that it has from 9 to 1 1 
feet height to the charging door. 

"Any further information desired on this subject I will 
cheerfully give if in my power through the columns of the 
'American Machinist' or by personal letter." 

The above is a fair sample of a wonderful cupola or melting 
record, that appears periodically in the mechanical and foundry 
publications of this country, and evidently from the reading of 
the above, they also appear in similar publications of other 
countries. 



2S6 THIC CUPOLA FURNACE. 

Can it be possible, that all the many cupola designers, cnpola 
experts, and cupola scientists of this country and Europe, have 
overlooked an important point, in simply charging of the 
cupola, and have been for years using from 50 to 60 per cent, 
more fuel than necessary to melt their iron? This would ap- 
pear to be the case, for Mr, Ramp claims to have done this 
rr.elting in an ordinary 30-inch cupola. Is it at all likely that 
all the manufacturers of standard cupolas, one of whom prob- 
ably made the one used by Mr. Ramp, have been underesti- 
mating the fuel ratio required in their cupolas 40 to 50 per 
cent.? Can it be that the thousands of foundrymen of this 
country and Europe have for years been using from 50 to 60 
per cent, more fuel than is actually necessary to melt their iron? 
It is not at all likely that all these practical and scientific men 
have made such a gross mistake in the estimating of fuel re- 
quired and manipulation of their cupola. Nor is it at all likely 
that Mr. Ramp melted 22 to 23 to i without counting the bed, 
and 14 to I counting the bed, anywhere but in his mind. For 
it is not pos-^ible to melt a five-ton heat in a 30- inch cupola 
with any such per cent, of fuel, let alone melting four and a half 
to five tons per hour. 

Mr. Ramp does not appear from the above statement of 
melting to understand the first principles of a cupola or to 
realize that it is a space furnace in which iron can only be 
melted within a given space, known as the melting zone. And 
iron must be sui'ported in this zone by the melting fuel imtil 
melted. Should it sink below this zone, after being converted 
into a semi fluid mass, it is struck by the blast, and conceited 
into slag by its bessemerizing action, and meliing at once stops. 

Should it descend to this point in a solid state, it is struck by 
the cold blast, and rapidly cooled. To support iron in a 
cupola, at the top of the melting zone, a bed of fuel is put in, 
that will fill the cupola to this point. Upon this bed a charge 
of iron is placed that may be melted while the fuel is burning 
away and settling to the lower edge of the zone or melting 
space. On the top of this iron a charge of fuel is placed of 



CUPOLA FUELS. 257 

sufficient depth or thickness to bring the top of the bed again 
up to the top of the melting zone. This fuel melts the next 
charge of iron, and so on through the heat. An excess of fuel 
in the bed or charges causes slow melting. And a deficiency 
of fuel causes dull iron and melting may stop entirely. The 
rule for charging is to place ten pounds of iron to one of fuel 
in the charges, when iron is not required to be very hot and 
fluid, and toward the end of a heat twelve to one may be 
charged. 

Mr. Ramp must have a bed of this height and he does not 
appear to make any extravagant claim for saving fuel in the 
bed. For without counting the bed, he claims to have melted 
22 to 23 to I. Now by what hocuspocus can he make a pound 
of coke melt 22 to 23 pounds of iron in his charges, while 
others can only melt 10 to 12 in cupolas of the same design 
and construction? He must either charm the fuel or the blast 
to obtain such results. 

Practical foundrymen pay no attention to any such articles 
that they may see in print, but all foundrymen are not practical 
foundrymen, and the reading of such stufT makes them think 
they are not getting the best of results in melting, and the fore- 
man is not a competent man for the position he holds, thus 
placing him under a cloud, and creating dissatisfaction, which 
may result in a vacancy for a foreman, which would seem to be 
the object of the writer of such articles. But there is a larger 
field for Mr. Ramp as an expert melter than as a foundry fore- 
man, for every founder would like to save 50 per cent, of his 
cupola fuel, and no doubt would be willing to pay liberally for 
points in melting that would enable him to do so. 
17 



CHAPTER XIII. 

FLUXING OF IRON IN CUPOLAS. 

Flux is the term applied to a substance which imparts 
igneous fluidity to metals when in a molten state, and has the 
power to separate metals contained in metallic ores from the 
non-metallic substances with which they are found in com- 
bination ; also to separate from metals when in a fluid state any 
impurities they may contain. Fluxes are also used for the pur- 
pose of making a fluid slag in furnaces to absorb the non- 
metallic residue from metals or ores and ash of the fuel, and 
removing them from the furnace to prevent clogging and to 
keep the furnace in good working order for a greater length of 
time. The materials used as fluxes for the various metals are 
numerous and varied in nature and composition, but we shall 
only consider those employed in the production of iron and the 
melting of iron for foundry work. 

The substances employed for this purpose are numerous, but 
they consist chiefly of the carbonate of lime in its various 
forms, the principal one of which is limestone. 

In the production of pig iron from iron ore in the blast fur- 
nace, limestone is used for the two-fold purpose of separating 
the iron from the ore, and for liquefying and absorbing the 
non-metallic residuum of the ore and ash of the fuel, and carry- 
ing them out of the furnace. For this purpose large quantities 
of limestone are put into the furnace with the fuel and ore. The 
stone melts and produces a fluid slag, which absorbs the non- 
metalHc residuum of the ore and ash of the fuel in its descent 
to the bottom of the furnace. Thence it is drawn out at the 
slag hole, and carries with it all those non-metallic substances 
which tend to clog and choke up the furnace. By this process 
of fluxing the furnace is kept in good smelting order for 

( 258 ) 



FLUXING OF IRON IN CUPOLAS. 259 

months, and even years. Were it not for the free use of lime- 
stone, the furnace would clog up in a few days. 

The blast furnace is a cupola furnace, and is constructed upon 
the same general principle as the foundry cupola. Foundry 
men long ago conceived the idea of using limestone as a cupola 
flux. In many foundries it is the practice to use a few shovel- 
fuls or a few riddlefuls of finely broken limestone in the cupola 
on the last charge of iron, or distributed throughout the heat, a 
few handfuls to each charge of iron. The object in using lime- 
stone in this way is not to produce a slag to be drawn from the 
cupola, but to make a clean dump and a brittle slag or cinder 
in the cupola, that can be easily broken down and chipped from 
the lining when making up the cupola for a heat. 

Limestone used in this way does not produce a sufficient 
quantity of slag to absorb the dirt from the iron and ash of the 
fuel and keep the cupola open and working free, but rather 
tends to cause bridging and reduce the melting capacity of the 
cupola. 

The making of a brittle cinder in a cupola by the use of lime- 
stone depends to a great extent upon the quality of the stone. 
Some limestones have a great afiFinity for iron and combine with 
it freely when in a molten state, while others have but little 
affinity for iron and do not enter into combination with it at all. 
In the cinder piles about blast furnaces we find cinder almost 
as heavy and hard to break as iron, resisting the action of the 
atmosphere for years; while at others we find a brittle cinder 
that crumbles to pieces after a short exposure to the atmos- 
phere, or even slacks down like quicklime when wet with water. 
In a cupola we may have a hard or brittle cinder produced by 
limestone. The results obtained from the use of limestone in 
small quantities in a cupola are so uncertain that we do not 
think they justify the foundryman in using it. 

LIMESTONE IN LARGE QUANTITIES. 

The tendency of slag or cinder in a cupola is to chill and 
adhere to the lining just over the tuyeres and around the cupola 



26o THE CUPOLA FURNACE. 

at this point, and prevent the proper working of the furnace. 
So great is this tendency to bridge that a small cupola will not 
melt properly for more than two hours, and a large one for 
more than three hours. To overcome this tendency to clog 
and bridge, foundrymen in many cases have adopted the bla'^t- 
furnace plan of using a large per cent, of limestone as a flux in 
their cupolas, and tapping slag. 

When a large per cent, of limestone is charged with the iron 
in a cupola, it melts when it settles to the melting point and 
forms a fluid slag. This slag settles through the stock to the 
bottom, and in its descent melts and absorbs the ash of the fuel 
and dirt or sand from the iron and carries them to the bottom 
of the cupola, where the slag and dirt it contains may be drawn 
ofT and the cupola kept in good melting order and in blast for 
days at a time. The amount of limestone required per ton of 
iron to produce a fluid slag depends upon the quality of the 
stone and the condition of the iron to be melted. It is the 
custom in some foundries, where the sprevvs and gates amount 
to from thirty to forty per cent, of the heat, to melt them with- 
out milling to remove the sand, and to use enough limestone in 
the cupola to produce a sufficient quantity of slag to absorb 
and carry out of the cupola the sand adhering to them. In 
this case a larger per cent, of limestone is required than would 
be necessary if the sprews and gates were milled and only clean 
iron melted. Poor fuel also requires a greater amount of slag 
to absorb the ash than good fuel, and a lean limestone must be 
used in larger quantities than a stone rich in lime. The quan- 
tity required to produce a fluid slag, therefore, varies with the 
quality of the limestone and the conditions under which it is 
used, and amounts to from 25 to lOO pounds per ton of iron 
melted. 

The weight of the slag drawn from a cupola when the sprews 
and gates are not milled, and the cupola is kept in blast for a 
number of hours, is about one- third greater than the weight of 
the limestone used. When the sprews and gates are milled, 
the weight of the slag is about equal to the weight of the lime- 



FLUXING OF IRON IN CUPOLAS. 261 

stone. When the cupola is only run for a short time and slag 
only drawn during the latter part of the heat, the weight of the 
slag is less than the weight of the limestone. 

The slag drawn from a cupola has been found by chemical 
analysis to contain from 4 to 7 per cent, of combined iron and 
numerous small particles of shot iron mechanically locked up 
in the slag. These cannot be recovered except at a greater 
cost than the value of the metal. In a number of tests made 
in the same cupola, w^e found the loss of iron to be from 3 to 4 
per cent, greater when the cupola was slagged. 

EFFECT OF FLUX UPON IRON. 

Many of the limestones and other mineral substances em- 
ployed as cupola fluxes contain more or less finely divided 
oxides, silicates, etc., in combination with earthy materials. 
The flux is often reduced in a cupola and its component parts 
separated, and in minute quantities they alloy with the iron and 
injure its quality. The combined efifect upon iron of these 
diffused oxides, silicates, etc., liberated in a cupola from their 
native element in fluxes, is to prevent the metal running clean 
in the mold or making sharp, sound castings, and the tensile 
and transverse strengths are frequently impaired by them. 
When the oxides, silicates, etc., are not separated in the cupola 
from their native elements, they do not impair the quality of the 
metal, nor do they improve it. The tendency of the cupola 
furnace is to clog and bridge over the tuyeres, and concentrate 
the blast upon the iron through a small opening in the center 
and injure its quality. If by the free use of limestone we pre- 
vent bridging and keep the furnace working open and free, we 
avoid injuring the iron in melting by the concentration of a 
strong blast upon it. The etTect, therefore, of limestone in a 
cupola is not to improve the quality of iron, but to prevent its 
deterioration in melting. 

THE ACTION OF FLUXES ON LINING. 

Limestone and other minerals employed as fluxes frequently 



262 THE CUPOLA FURNACE. 

contain impurities which enter into combination with the h'ning 
material of a furnace and render it fusible. This was illustrated 
at the foundry of John D. Johnson & C6., Hainesport, N, J., in 
1893. The cupola front had been put in with new molding 
sand for a long time, and no fllux used in the cupola. The sand 
made an excellent front that resisted the action of the heat and 
molten iron upon it. As the heats enlarged, it became neces- 
sary to use flux and tap slag to run off the heat. Oyster shells 
were used, and produced a slag that flowed freely and had no 
effect upon the sand in the front. When the supply of shells 
became exhausted, a limestone was used in place of them. 
Trouble then began with the front. It was melted by the flux 
into a thick, tough slag that settled down and closed up the tap 
hole, and iron could only be drawn by cutting away a large 
portion of the front to enlarge the tap hole. Mr. Johnson 
called at our office to learn what could be done to keep the tap 
hole open. We advised that the front material be changed and 
a mixture of fire-clay and sharp sand be used in place of mold- 
ing sand. This was done, and there was no further trouble in 
keeping the tap-hole open and in good order to run ofT the 
heat. This serves to illustrate the efifect of fluxes upon lining 
material. With no flux and with oyster shells the molding 
sand resisted the heat and pressure of molten iron and slag 
upon the front; but with limestone it melted into a thick, 
tough slag. This was due to some property in the limestone 
entering into combination with the sand and making it fusible. 
Had the cupola been lined with this molding sand, the entire 
lining would have been cut out in one heat, while it would have 
stood many heats with shells or no flux at all. 

From the various qualities of cupola brick and lining material 
now in the market, a lining may be selected that will resist the 
action of almost any flux or slag, and foundrymen may select 
a flux to suit the lining or a lining to suit the flux, whichever 
they find to be the most profitable in their locality. 



FLUXING OF IRON IN CUPOLAS. 263 

HOW TO SLAG A CUPOLA. 

Foundrymen sometimes experience trouble in slagging their 
cupolas. This is largely due to a lack of knowledge in charg- 
ing the limestone and drawing the slag, for any cupola can be 
slagged if properly worked. To draw slag from a cupola, a 
sufficient quantity of limestone or other slag-producing material 
must be charged in the cupola with the iron to make a fluid 
slag. The exact amount required can only be learned by ex- 
perimenting with the fluxing material used, but it is generally 
from fifty to sixty pounds of good limestone per ton of iron, 
when the remelt is not milled. The limestone is generally 
charged on top of the iron and put in with each charge after 
the melter begins using it. No limestone is used with the iron 
on the bed or first few charges of iron. In small cupolas lime- 
stone is generally charged with the second or third charge of 
iron. In large cupolas, when the charges of iron are light, six 
or eight charges, or generally about one-sixth of the heat, are 
charged without limestone. This is the way limestone is used 
when the cupola is run in the ordinary way for a few hours. 
When the cupola is run for some special work, the limestone is 
charged in a number of dififerent ways. 

The slag is drawn from the cupola through an opening known 
as the slag-hole. This opening is made through the casing and 
lining under the low er level of the tuyeres and at a point in the 
cupola where it will be out of the way in removing iron from 
the spout and convenient for removing the slag. The height 
the slag-hole is placed above the sand bottom depends upon 
how the iron is drawn from the cupola. When it is desired to 
hold iron in a cupola until a sufficient quantity is melted to fill 
a large ladle, the slag-hole is placed high, and when the iron is 
drawn as fast as melted the slag hole is placed low. When the 
slag hole is placed high, slag can only be drawn as the cupola 
fills up with iron and raises it to the slag-hole. When the iron 
is withdrawn from the cupola, the slag falls and the slag-hole 
is closed with a bod to prevent the escape of blast. When the 
iron is drawn from the cupola as fast as melted, the slag-hole is 



264 THE CUPOLA FURNACE. 

placed low, and when opened it is permitteil to remain open 
through the remainder of the heat. This is the best way of 
drawing slag from the cupola, for the flow is regulated by the 
amount of slag in the cupola, and if the hole is not made too 
large, there is no escape of blast. 

The slag in the bottom of a cupola takes up impurities from 
the fuel and iron, and if permitted to remain in the cupola for 
too long a time, it may become so thick and mucky it will not 
flow from the slag hole. Or it may be filled with impurities, 
become over- heated, boil up and till the tuyeres with slag ; and 
when boiling, it will not flow from the cupola through a small 
slag hole. The time for drawing the slag from a cupola is 
therefore a matter of great importance. The slag hole is gen- 
erally opened in from half an hour to an hour after the cupola 
begins to melt, and when placed low is permitted to remain 
open throughout the remainder of the heat. When placed so 
high that slag can only be drawn when the cupola fills up with 
molten iron, it should be opened as soon as the slag begins to 
rise and closed as soon as it falls below the opening. 

DOES ir PAY TO SLAG A CUPOLA ? 

Nothing is gained by slagging a cupola when the sprews and 
gates are milled and the heat can be melted successfully in the 
cupola without slagging; but a great saving in labor and wear 
and tear of machinery can be efifected in many foundries by 
melting the sprews and gates with the sand on, and slagging 
to carry the sand out and keep the cupola working free. A 
cupola cannot be made to melt iron faster by slagging, but it 
can be kept in blast and in good melting condition for a greater 
length of time and a much larger amount of iron melted by 
slagging. Foundrymen who find their cupolas temporarily too 
small to melt the quantity of iron required for their work, can 
overcome the difficulty by slagging the cupola and keeping it 
in blast for a greater length of time. 

In endeavoring to make an estimate of the cost of slagging a 
cupola, we found that the cost of limestone in different localities 



FLUXING OF IRON IN CUPOLAS. 265 

varied from 50 cents to $3 per ton. The amount used varied 
from 25 to 100 pounds per ton of iron melted. The amount of 
slag drawn varied from 25 to 100 pounds per ton of iron. The 
iron combined with the slag varied from 4 to 7 per cent. With 
these wide differences in the cost and quantity of limestone 
used, and the difference in the quantity of slag drawn and per 
cent, of iron it contained, we found it impossible to make an 
estimate that would be of any practical value to foundrymen. 
Such an estimate must be made at each foundry to be of value. 

* SHELLS. 

Oyster, clam and other shells are largely composed of lime, 
and are frequently used as a flux in place of limestone in local- 
ities where they can be procured at a less cost than the latter. 
The shells are charged in the same way as limestone and in 
about the same proportion to the iron. They may be used in 
place of limestone either in large or small quantities, and have 
about the same efifect upon the iron and cupola as limestone. 
When used in large quantities, they produce a fluid slag that 
keeps the cupola working free and flows freely from the slag- 
hole, carrying with it the refuse of melting that clogs the 
cupola. When the heat first strikes shells in a cupola, they 
produce a crackling noise and flakes of shell may be seen to 
pass up the stack, and the foundry roof, when flat, is often 
covered with flakes of shell after a heat, when they are used 
in large quantities. The crackling is due to the destruction of 
the hard inner surface of the shell; the flakes thrown from the 
cupola are entirely of this surface, and the loss of shell is not 
so great as it would appear to be at first sight. The remainder 
of the shell melts and forms a fluid slag that absorbs the refuse 
of melting, becomes thick and helps to clog up a cupola when 
the shells are used in small quantities, or assists in keeping it 
open when used in large quantities. 

MARBLE SPALLS. 

Marble is another of the carbonates of lime, and the spalls or 



266 THE CUPOLA FURNACE. 

chippings from marble quarries or works are quite extensively 
used in some localities as a cupola flux. Their action in a 
cupola and their effect upon iron is very similar to that of lime- 
stone, and they are used in the same way and in about the 
same proportions. There are a number of other substances, 
such as fluor-spar, feld-spar, quartz-rock and a number of 
chemical compounds that are used as cupola fluxes. 

In 1873, when engaged in the manufacture of malleable iron, 
we began experimenting with mineral and chemical materials 
with the view of making a cheap malleable iron, and changing 
the nature of iron in a cupola furnace so that it might be an- 
nealed at a less cost, and produce stronger iron. In this we 
succeeded to some extent, and then drifted off into improving 
the quality of iron in a cupola for grey iron castings; this we 
have followed for nearly twenty years. During this time we 
have melted iron in foundries all over the greater part of the 
United States and Canada, and have constructed and worked a 
number of experimental cupolas of our own, to learn the effect 
of different mineral and chemical substances upon iron and 
cupola linings. In these investigations we have used all the 
mineral and chemical fluxes known to metallurgical science, and 
observed their effect upon the various grades of iron employed 
for foundry work. 

In these experiments it was found that iron can be improved 
or injured when melted in a cupola furnace, and is often ruined 
as a foundry iron by improper melting and fluxing. The point 
at which iron is melted in a cupola has a great deal to do with 
its quality. Iron melted too high in a cupola is burned and 
hardened ; melted too low, it runs dirty in a mold ; melted 
with too strong a blast, it is hardened. Iron melted dull does 
not make a sound casting. Iron melted with poor coal or coke 
is injured by the impurities in the fuel. Iron melted with oyster 
shells, limestone and other mineral fluxes may take up oxides, 
sulphides, phosphides, silicates and other impurities contained 
in the flux and may be ruined by them for foundry work. 

The per cent, of iron lost in melting is increased by improper 



FLUXING OF IRON IN CUPOLAS. 267 

melting and fluxing, and may be double or treble what it should 
be. We have made a great many experiments to ascertain the 
effect of silicon on iron, and have found that silicon enters freely 
into combination with cast iron and has a softening effect upon 
it. Iron as hard as tempered steel may be made as soft as lead 
by combining it with silicon. But silicon is an impurity hav- 
ing a deleterious effect upon iron. An excess of it destroys 
cohesive force and crystallization, and reduces transverse and 
tensile strength. So great is the destruction of cohesive force 
in cast iron by silicon that the strongest iron may be reduced 
to a powder when combined with an excess of silicon, Silicon 
in any proportion is a detriment to cast iron, as an iron. The 
nature and form of crystallization of a pure cast iron is changed 
by sudden cooling in a mold, and a soft iron in the pig may 
become a hard iron in a casting. This chilling property in 
cast iron is destroyed by silicon, and an iron high in it is not 
hardened when run into a sand mold or upon an iron chill. 
The destruction of the chilling tendency in cast iron is very de- 
sirable in the manufacture of light castings, and for this reason 
silicon irons are largely used in foundries making this class of 
work. 

The per cent, of silicon an iron may contain and yet retain 
sufficient cohesive force for the work, depends upon the amount 
of other impurities in the iron and the work the iron is em- 
ployed to make. For heavy work, requiring great strength, it 
should contain none at all, For light machinery it may con- 
tain from one-half to one per cent ; and for stove plate, light 
bench work, etc., it may contain from two to three per cent. 
These amounts arc sufficient to reduce the chilling tendency of 
the iron, without impairing its strength to any great extent in 
these classes of work. But a larger amount destroys the 
strength of the iron and also injures its flowing property in 
a mold. 

At the present time there is a large amount of high-silicon 
cheap Southern iron being used in stove foundries for the pur- 
pose of making a cheap mixture and a soft casting. At one of 



268 THE CUPOLA FURNACE, 

these foundries we recently visited, the foreman informed us that 
they were using a mixture that cost $14 per ton, and said their 
breakage in the tumbling barrels and mounting shop was very 
large, and he never made a shipment to their warehouse in 
New York, a distance of 25 miles, but a lot of stoves were 
broken in transit and sent back to be remounted and repaired. 

At another stove foundry in Troy, N. Y., they informed us 
they were using a mixture of Pennsylvania irons that cost them 
$20 per ton. They had scarcely any breakage at their works, 
and shipped their lightest stoves and plate to their warehouse 
in Chicago without boxing or crating, and never had any break- 
age in transit or in handling. They had found by experience 
that a mixture of Pennsylvania irons at a cost of $20 per ton 
was cheaper in the long run than a mixture of cheap Southern 
irons at $14 per ton. 

In a number of other foundries we visited they all complained 
of heavy breakage when using high silicon irons as softeners. 
Another matter to be considered in using these high silicon 
irons for stove plate is, how long will a stove last made of such 
weak iron, and can a reputation for good work be maintained 
by foundries using them? A stove made of this kind of iron 
will certainly not last so long as one made of good iron. 

Carbon has the same effect upon cast iron as silicon in soften- 
ing and reducing the chilling tendency. The hardest of cast 
iron can be made the softest by the addition of carbon, without 
destroying its cohesive force and rendering it brittle or rotten, 
and carbon can be added to iron in a cupola as readily as sili- 
con. Before the high-silicon Southern irons were put upon 
the Northern market highly carbonized irons were used as 
softeners for stove plate and other light work, and a far better 
grade of castings was made then than now is made from the 
silicon irons. 

It is difificult to remove silicon from iron when melted in a 
cupola, but free carbon is readily removed by the oxidizing 
flame produced by a strong and large volume of blast; and a 
soft iron may be hardened in melting to such an extent as to 



FLUXING OF IRON IN CUPOLAS. 26y 

make it unfit for the work. This can be prevented to some 
extent by using a mild blast and melting the iron low in the 
cupola, and it can also be prevented by the use of chemicals to 
produce a carbonizing flame. 

We have spent a great deal of time and money in experiment- 
ing on the production of such a flame in a cupola as would not 
only prevent the deterioration of iron in melling, but would 
improve its quality, and at the present time are engaged in the 
manufacture of a chemical compound for this purpose. 

FLUOR SPAR. 

Fluor spar is extensively used as a cupola flux, in sections 
of the country where it is found native and can be procured at 
a moderate cost, and it has also been used to a considerable 
extent in other sections of the country, but the expense of 
transporting this heavy material has greatly retarded its use as 
a flux at any great distance from the mines. Fluor spar when 
used in sufficient quantities in a cupola produces a very fluid 
slag that absorbs and liquefies the non-metallic residue of melt- 
ing with which it comes in contact, keeps the cupola open and 
working freely, and causes it to dump clean. But it also fluxes 
the cupola lining, causing it to burn out in a very short time, 
and for this reason it can only be used in large quantities with 
certain grades of lining material that are only affected to a very 
limited extent by it. This quality of lining material can gen- 
erally be procured in the vicinity of the mine, but it cannot 
always be had at a moderate cost in other parts of the country, 
and for this reason fluor spar is frequently used with limestone 
to increase the fluxing properties of the latter and reduce 
its own injurious effect upon the cupola lining. When used 
in this way fluor spar greatly increases the efficiency of a 
poor limestone, and often enables a founder to use a cheap 
limestone that could not be employed alone as a flux, while the 
limestone reduces the injurious effect of the spar upon the lin- 
ing, and the two combined make an excellent flux for tapping 
slag in long heats. 



270 THE CUPOLA FURNACE. 

We have used fluor spar in a number of cupolas and with a 
great many difterent brands of iron. We never found it to 
harden or soften any of these irons to a noticeable extent, but 
it improved the melting very materially in a number of cases 
where the cupola was run beyond its melting capacity, melted 
slow in the latter part of the heat, and could not be dumped 
without a great deal of labor. 

CLEANING IRON BY BOILING. 

Before the use of fluxes in cupolas was so well understood 
as at the present time, it was a common practice in many 
foundries to cleanse iron of impurities in a ladle by agitating 
or boiling the molten metal. This caused a large amount of 
dross to collect on the surface, from which it was skimmed ofif 
and the iron was considered to be purer after the boiling. A 
favorite way of agitating iron in a ladle was to place a raw 
potato or apple on the end of a tap bar and hold it in the 
molten metal, near the bottom of the ladle, for a short time. 
The potato or apple contained a sufficient amount of moisture 
to agitate or boil the metal gently without exploding it, and 
the metal was said to be greatly benefited by this gentle boil- 
ing; but practice has demonstrated that nothing is gained by 
boiling iron in a ladle, and it lias long been discontinued in this 
country. 

A ball of damp clay placed upon the end of a tap bar was 
also used for boiling iron in a ladle, but this was not considered 
so good or so safe as an apple or potato, for if the clay chanced 
to be too damp, it caused the iron to boil violently and some- 
times to explode. 

Another favorite way of cleansing and mixing irons years 
ago was to pole the molten iron. This was done with a pole 
two or three inches in diameter, of green hickory or other hard 
wood. The pole was thrust into the molten metal in a ladle or 
reverberatory furnace, and the metal stirred with it. The effect 
of the green wood thrust into the metal was to cause it to boil 
around the pole, and as the pole was moved through the metal 



FLUXING OF IRON IN CUPOLAS, 2/1 

all parts of it were agitated, and a better mixture of the 
different grades of iron melted was effected and a moie homo- 
geneous casting produced. The poling of iron was a common 
practice in many foundries twenty-five years ago, but we have 
not seen it done in a ladle for many years, and we believe the 
practice has been entirely discontinued with cupola-melted 
iron ; but poling is still practiced in many foundries in the mix- 
ing of iron in reverberatory furnaces for rolls and other cast- 
ings requiring a very strong homogeneous iron. 



CHAPTER XIV. 

WHAT A CUPOLA WILL MELT. 

The cupola furnace was originally designed for melting cast 
iron for foundry castings, and at the present time is principally 
employed for that purpose, but it is now also used in the melt- 
ing of almost all of the various grades of manufactured iron 
and steel, and many other metals. 

It is extensively employed in the melting of pig iron, in the 
manufacture of Bessemer steel, and in the melting of iron for 
castings to be converted into steel and malleable castings after 
they are cast. It is also used in melting steel for steel cast- 
ings, but as it makes an uncertain grade of steel it is only em- 
ployed for the more common kinds of castings. 

It is also employed in melting tin-plate scrap, sheet iron, 
wrought iron and steel wire, gas-pipe, bar iron, horse-shoes 
and all the various grades of m.allcable wrought and steel scrap 
found in a promiscuous pile of light scrap and used in the 
manufacture of sash, elevator and other weights, and melts 
them readily, producing a very hot fluid metal, and when prop- 
erly managed is the very best furnace for this purpose. 

It is to some extent used in the smelting of copper ores and 
the melting of copper in the manufacture of brass, and also in 
the melting of brass for large castings; but in melting brass, 
the alloy is oxidized to so great an extent that an inferior 
quality of brass is produced to that obtained from crucibles. 

Lead is frequently melted in cupolas. It melts more slowly 
than would naturally be expected, and it is very difficult to re- 
tain it in a cupola in the molten state, as it is almost impossible 
to put in a front through which it will not leak, and the ladle is 
generally heated and the tap hole left open. 

The quantity of cast iron that can be melted in a cupola per 

(272) 



WHAT A CUPOLA WILL MELT. 273 

hour depends upon its diameter and height, and at the 
present time varies from one hundred pounds to twenty tons. 
Tiie number of hours a cupola will melt iron freely when 
properly managed, is only limited by the length of time the 
lining will last. Cupolas have been run continuously from 
one o'clock Monday morning until twelve o'clock Saturday 
noon, melting fourteen tons per hour. 

The size and weight of a piece of cast-iron that can be 
melted in a cupola at one heat, depends upon the size of the 
cupola. 

As a rule, any piece of iron that can be properly charged in 
a cupola can be melted. In steel-works cupolas, ingot moulds 
weighing five tons are melted with ease in the regular charges 
of the cupola. 

At the foundry of the Pratt & Whitney Co., Hartford, Conn., 
a large charging opening is placed in the cupola for the pur- 
pose of charging large pieces of iron to be melted, and almost 
any piece can be melted in one heat that can be placed in the 
cupola. 

At the foundry of the Lobdell Car Wheel Co., Wilmington, 
Del., an oblong cupola with charging door placed at the ends 
was constructed shortly after the War of the Rebellion to melt 
cannon and other heavy government scrap, and large cannon 
weighing many tons were melted in the cupola without previ- 
ously breaking them up. 

MELTING LARGE PIECES OF IRON. 

In jobbing and machine foundries, bad castings are some- 
times made or pieces purchased in scrap that are considered 
too large to melt in the cupola and cannot be broken with the 
appliances at hand for breaking. Such pieces are frequently 
permitted to lie in the foundry yards for years, and if thej-' 
chance to be bad castings, may often be buried, as we have 
frequently seen them, by the foreman or molders to get them out 
of sight. Such pieces are frequently permitted to lie in the 
yard through lack of knowledge of melting or of what consti- 
18 



274 THE CUPOLA FURNACE. 

tutes a large piece to melt in a cupola; and a few words on 
this subject may be of value. 

What constitutes a large piece of iron to be melted in a 
cupola depends upon the size of cupola. 

A piece weighing a few hundred weight may be a large piece 
for one cupola, while a piece weighing several tons may not be 
a large piece for another. A good way to decide this is by the 
weight of iron placed upon the bed when charging. 

A piece of iron weighing no more than the weight of small 
iron placed on the bed or charge is not a large piece to melt, 
and may be charged and melted the same as sma'l iron in reg- 
ular heats. Such pieces should be put in after the first or 
second charge, that they may have time to heat before settling 
into the melting zone. No extra fuel should be used in melt- 
ing such pieces, for extra fuel places the pieces too high in 
the cupola, makes the cupola melt slow, and may be the cause 
of failure to melt the piece. Large pieces weighing three or 
four times the weight of a charge cannot be melted in this way, 
for the piece may not all be melted, before the molien iron 
comes down too dull for pouring, and such pieces should be 
melted alone. 

When melting such pieces an extra bed of about six inches 
should be put in for the purpose of heating the iron prepara- 
tory to melting, before settling into the melting zone, and fuel 
should be placed around the piece to concentrate the heat 
upon it. 

.In this way iron may be melted sufficiently hot for casting, 
but if considerable fuel cannot be placed around the piece, the 
iron will come dull after an amount equal to two or three 
charges has been melted. 

When this occurs and the iron begins to melt slow, all the 
melted iron should be drawn ofT and the bottom at once 
dropped to prevent the unmelted piece being lodged in the 
cupola, and the piece again charged in the same way for an- 
other heat. In this way any piece of iron that can be placed 
in a cupola may be melted. 



WHAT A CUPOLA WILL MELT. 275 

MELTING TIN PLATE SCRAP IN A CUPOLA. 

Tin plate scrap is melted in the ordinary foundry cupola the 
same as cast iron scrap, but more fuel is required to melt it. 
The best results are obtained with i pound of coke to from 3 
to 4 pounds of scrap and a mild or light blast. Various ways 
of preparing the scrap for charging, such as hammering or 
pressing it into ingots and forming it into compact balls, have 
been tried ; but as good results are obtained by charging it in 
bulk, and it is generally placed in the cupola in this way. The 
charges are made of about the same weight as charges of iron 
in a cupola of similar size, but more fuel is added. The scrap 
when first put in the cupola is very bulky and takes up a good 
deal of room, but when heated it settles down into a compact 
mass, and takes up very little more space than a charge of cast 
iron scrap. Tin plate scrap settles rapidly, but melts slower 
than cast iron scrap or pig. 

Numerous attempts have been made to recover the tin de- 
posited upon the iron by heating the scrap in various ways to 
a temperature at which tin melts, but the coating of tin is so 
light it will not flow from the iron. All such attempts to re- 
cover it have proved failures. The iron, or rather steel, which 
is coated with tin is a very soft and tough material, but when 
melted the tin alloys with it, and the metal produced is very 
hard and brittle. The molten metal from this scrap has very 
little life, chills rapidly in the spout, ladles or molds, must be 
at a white heat when drawn from the cupola, and must be 
poured as quickly as possible. When not melted extremely 
hot the metal expands or swells in cooling to so great an ex- 
tent as to tear a sand mold to pieces or break an iron mold 
where it cannot escape. When the metal is melted very hot 
this expansion does not take place to so great an extent, and a 
sand or iron mold may be used for any work into which it is to 
be cast. 

The molten metal is more susceptible to the effect of mois- 
ture than iron, and is instantly thrown out of a mold when 
sand is worked too wet and cannot be made to lie in it. The 



2/6 THE CUPOLA FURNACE. 

sand must, therefore, be worked as dry as possible. The metal 
is very hard and brittle, and only fit for sash and other weights, 
and even these when light and long must be handled with care 
to avoid breaking. The weights when rough cannot be chipped 
or filed smooth, and sash weights made of this metal are gen- 
erally sold at a less price than iron weights ; for when rough 
they wear out very quickly the wooden box in which they are 
hung, and builders dislike to use them. A foundryman who 
recently had a contract from the government for a number of 
weights of several tons each, to be used for holding buoys in 
the ocean, made them from tin plate scrap. When cast they 
were so rough that he remarked it was a good thing they were 
to be sunk in the mud under the ocean, for they were not fit to 
be seen. 

In a number of experiments we made in melting this scrap,, 
we found we could produce a gray metal from it about as hard 
as No. 3 pig iron, by melting it with a large per cent, of fuel 
and a very light blast. But the metal was very rotten and had 
little if any more strength than when white. We tried a number 
of experiments to increase its strength, but in none of them did 
we succeed to any extent. Melting it very hot and running it 
into pigs and remelting the pig improved the strength in some 
degree ; but this was expensive, and the results did not justify 
the expense. W^e also made a number of tests to learn the 
amount of metal lost in melting this scrap, and found with a 
light or proper amount of blast to do good melting there was 
practically no loss. With a strong blast the loss was heavier, 
and in one heat, with a very heavy blast, we lost lo per cent, 
of the metal charged. The metal from this heat was a little 
stronger and also a little harder, which was probably due to 
oxidation of the tin from the iron by the strong blast before 
melting. In melting old roofing tin, rusted scrap and old cans, 
the loss in melting varied frm lo to 25 per cent., which was 
probably due to rust, paint and solder used in putting the work 
together. 

Tin acts as a flux when melted with iron, and renders it more 



WHAT A CUPOLA WILL MELT. 277 

fusible. Scrap from which the tin has been removed by acids 
to recover the tin or by the process employed in the manu- 
facture of chloride of tin, is more difficult to melt in a cupola 
than when covered with tin, and more fuel and time are re- 
quired to melt it, but a better grade of iron is produced from it. 
Scrap of this sort should be melted soon after the tin is removed 
from it, for it rusts very quickly, and when rusted to any extent 
produces nothing but slag when melted. 

Scrap sheet iron is more difificult to melt than tinned scrap 
and is seldom melted in a cupola, for better prices are paid for 
it by rolling mills than foundrymen can afford to offer. 

Galvanized sheet-iron scrap cannot be melted at all in a 
cupola in large quantities, for the zinc used in galvanizing it, 
acts like the zinc solution used in the Babcock fire extin- 
guishers, and reduces the heat in the cupola to a marked degree. 
When melting tinned scrap any galvanized scrap that has been 
mixed with it must be carefully picked out, for even in small 
quantities it lowers the heat in a cupola to such an extent that 
the metal from the tinned scrap cannot be used, and must be 
poured into the pig bed if it runs from the cupola at all. There 
are a number of ways of doctoring the metal from tin-plate 
scrap when it melts or flows badly, by the use of gas and oil, 
retort carbon, etc., but they do not improve the quality of the 
metal to any extent, and it is very doubtful if they increase its 
melting and flowing properties. 

A cupola of any suitable size can be employed for melting 
tin-plate scrap and an entire heat of the scrap may be melted 
alone, or it may be mixed with cast-iron scrap or pig, and 
melted, or again, it may be melted alone directly after a heat 
of iron. It is a common practice in many small foundries to 
melt this scrap in the cupola for sash and other weights directly 
after melting a heat of iron for soft castings. An extra heavy 
charge of fuel is placed upon the last charge of iron to check 
the melting for a few minutes by preventing the scrap settling 
into the melting zone, and the soft iron is all melted and drawn 
off before the scrap begins to come down. In melting long 



2/8 THE CUPOLA FURNACE. 

heats of this scrap it is necessary to flux the cupola with lime- 
stone or shells in sufficient quantities to produce a fluid slag. 
The flux should be put in on the first charge of scrap in very- 
small cupolas and on the second or third charge in large cu- 
polas, and on each charge throughout the heat afterward. The 
slag hole should be placed at the lowest point consistent with 
the amount of molten metal to be collected in the cupola at one 
time, and opened as soon as the first charge of scrap, upon 
which flux is placed, has melted. The slag hole may be opened 
and closed from time to time, but it is better not to make the 
hole too large, and leave it open throughout the heat. The 
flow of slag then regulates itself, and there is no danger of it 
running into the tuyeres. In melting a few hundredweight of 
this scrap in a cupola, after melting a small heat of iron, it is 
not necessary to charge flux in sufficient quantities to produce 
a fluid slag to be tapped, unless the cupola is very small and 
shows signs of bunging up. In this case flux must be charged 
with the iron, and slag tapped early in the heat, to keep the 
cupola in condition to melt the scrap after the iron is melted. 
When constructing a-cupo]a expressly for melting tin-plate 
scrap the charging door or opening should be placed about 6 
inches above the scaffold floor, so that the scrap may be 
dumped in from a barrow and save handling it a second time 
with forks. The charging door should be much larger than in 
a cupola of the same diameter for melting iron, and should be 
not less than 3 or 4 square feet in any case, and for cupolas of 
very large inside diameter the opening should be equal to one- 
half or three-fifths the diameter of the shell, and 4 or 5 feet 
high. The height of the door above the bottom depends upon 
the diameter of the cupola. In large cupolas it should be 
placed 18 or 20 feet above the bottom and in smaller cupolas 
as high as possible without danger of the stock hanging up in 
the cupola before settling into the melting zone. The lining 
material must be carefully selected, for poor fire brick will not 
last at the melting zone through one long heat; in fact, none 
of the fire brick lasts very long at this point, and it is generally 



WHAT CUPOLA WILL MELT. 279 

necessary to put in a few new ones after each heat. High 
silicon brick is said to last belter than any other brick, but 
some of the native stone linings which we have described last 
longer in melting this scrap than any of the fire brick, and 
they are generally used for lining cupolas for this work. The 
cost of melting tin-plate scrap in a cupola is from $1 to $2 per 
ton more than the cost of melting iron. The amount of profit 
in melting this scrap for weights, etc., depends, like all other 
foundry business, upon the location and size of the plant and 
the management of the business; but at the present time, even 
under favorable circumstances, the profits are small. 

MtLTING BRASS IN A CUPOLA. 

The cupola furnace presents advantages not found in any 
other furnace for melting alloyed yellow brass, red brass, 
bronzes, etc. It melts these alloys more rapidly, hotter and 
with less fuel than probably any other furnace, and has been 
adopted at the United States Navy Yard, Washington, D. C. for 
melting allo}s for all large castings of these metals. The 
Southern R. R. Co. have constructed a small cupola in their 
repair shop foundry, Manchester, Va., for remelting axle bear- 
ings for locomotives and cars, and other castings, and cupolas 
have been installed in many other plants for this purpose. 
The cupola is not the best furnace for making alloys, for the 
more fusible metals melt too rapidly for those requiring a 
higher and more prolonged heat and it is difficult to obtain a 
definite alloy from a cupola. But copper and other metals 
having high melting points, maybe melted in a cupola and the 
more fusible metals melted in another furnace, and an accurate 
alloy can then be made in a ladle which had been previously 
well heated. In melting alloyed metals in a cupola, the loss 
of metal is no greater than in a crucible, and by some founders, 
who have made tests is claimed not to be so great. The cupola 
also presents the advantage of being able to mould all day, and 
having an hour for casting which greatly increases the output 
of a foundry over the method of casting when a crucible of metal 
is ready for pouring. 



CHAPTER XV. 

ART IN MELTING. 

The melting of iron in a cupola is an art that is by many 
foundrymen and foundry foremen but little understood, and 
they never begin the melting of a heat without a dread that 
something will happen to prevent the iron being hot enough 
for the work, or that they may not be able to melt the entire 
heat. In many foundries it is almost an every-day occurrence 
to have something happen in or about the cupola to prevent 
good melting. The sand bottom cuts through, the front blows 
out, the tap hole cannot be opened without a heavy bar and 
sledge, slag flows from the tap hole with the iron and bungs 
up the spout and ladles, iron and slag get into the tuyeres, 
daubing falls off the lining and bungs up or bridges the cupola, 
stock lodges upon the lining in settling, and only part of the 
heat can be melted. Iron melts so fast in one part of the heat 
that it cannot be taken care of; in another part it melts so 
slowly that a ladle cannot be filled before the iron is too dull 
for the work ; or, iron is not melted of an even temperature 
throughout a heat, and has to be watched in order to get hot 
iron to pour light work; the first iron is dull, or the last is 
dull, or the whole heat is dull. Some of these troubles to a 
greater or less extent occur almost daily, and it is a rare occur- 
rence in a great many foundries that a perfectly satisfactory 
heat is melted. In foundries in which these difficulties occur, 
the foundryman or his foreman, or both, do not understand 
melting, the cupola is in charge of an old professional melter, 
who always ran it in this way, or a foundry laborer or helper 
has been selected for a melter and given a few instructions by 
some one who has seen a cupola prepared for a heat, or per- 
haps has melted a few heats. He is instructed until he melts a 

(280) 



ART IN MELTING. 28 1 

heat successfully, and then he " knows it all," and is left to 
himself, and perhaps he knows as much as his instructor. If 
he is a practical man, he learns the cause of all the troubles in 
melting and in time becomes a fair melter; but at what an ex- 
pense to his employer ! 

If he is not a practical man, he bungles along from day to 
day until he gets disgusted with his job and quits, or is dis- 
charged, and another man of the same kind is tried, with about 
the same result, for there is no one about the foundry who 
understands the art of managing a cupola to instruct him, and 
he must learn it himself, or as a melter be a failure. The foun- 
dryman or foreman of a foundry in which this kind of melting 
is done, will tell you a cupola is a very hard thing to manage, 
and it cannot be made to melt evenly throughout a heat or the 
same every heat. If this were really the case foundries making 
very light work, requiring hot fluid iron, would lose half their 
castings every heat or be compelled to pour large quantities of 
iron into the pig bed, and wait for hot iron. But this is not the 
case in stove, bench and other foundries making very light 
castings. Heats of many tons are melted every day, and as 
many pounds of iron are melted in one minute as in another 
from the beginning to the end of a heat, and there is not a 
variation of fifty degrees in the temperature of the iron from 
the first to the last tap. 

There is no chance work in nature, and there is no chance 
work in art when the scientific principles are understood and 
applied to practice, and there is no chance work in melting 
iron in a cupola when the cupola is scientifically managed, and 
there is no furnace used for melting iron more easily managed 
than the cupola furnace ; but it is necessary to understand its 
construction and mode of operation to do good melting. 

In the first place, the cupola must be properly constructed 
and of a size suitable for the amount of iron to be melted, and 
the time in which this melting is to be done. For fast melting, 
a cupola of large diameter is required, and for slow melting 
one of small diameter. There are those in use at the present 



282 THE CUPOLA FURNACE. 

time in which sixty tons of iron are melted in four hours, and 
those in which one ton of iron is melted in four hours and a 
half, and each of these cupolas melts iron as fast as it can be 
taken care of after it is melted. The large cupola would be 
useless in one foundry, and the small one in the other. So it 
follows that a cupola must be so constructed as to be suitable 
for the melting it is desired to do. 

To melt iron hot and of an even temperature, the tuyeres 
must be placed low, made of a size to admit the blast freely to 
the cupola, and arranged to distribute the blast evenly to the 
fuel, and the latter must be of a proper volume for the size of 
cupola. To utilize the greatest possible amount of heat from 
the fuel, the charging door should be placed high and the cu- 
pola kept filled to the door until the heat is all in. When pre- 
paring a cupola for a heat, it must be properly ch'pped out 
and the lining given the best possible shape for melting, by the 
application of daubing. The daubing material must be of an 
adhesive and refractory nature and not put on so thick that it 
will fall off when dried or heated. The bottom door must be 
put up and supported by a sufficient number of props to make 
it rest perfectly solid against the bottom plate. The bottom 
sand must be of a quality that will not burn or be cut up by the 
molten iron, and it must be of a temper that will neither wash 
nor cause the iron to boil. It must be carefully packed around 
the edges and rammed evenly, and no harder than the sand for 
a mould, and given a proper pitch to cause the iron to flow to 
the tap hole as fast as melted. A front and spout lining mater- 
ial must be selected or prepared that will not cut or melt. And 
the front must be put in solid with a proper sized tap hole, 
and the spout given the right shape and pitch. The cupola 
having been thus prepared, it is ready for melting. Shavings 
and wood are put in for lighting the melting fuel or bed, and a 
sufficient quantity of coal or coke is put in to fill the cupola to 
the top of the melting zone after it has settled. As soon as 
this fuel is well on fire, and the heavy smoke is burned ofT so 
that the top of the bed can be seen, it is leveled up with a few 



ART IN MELTING. 2.^3 

shovelfuls of fuel, and charges of iron and fuel are put in until 
the cupola is filled to the door. The weight of the bed fuel, 
and charges of iron and luel, must be learned for each cupola, 
for scarcely any two are charged exactly alike. 

It will thus be seen that the melting of iron in a cupola is 
very simple. But all these things and many more must be 
learned and practiced to make it so, and they cannot be learned 
in one or in a dozen heats. Sl.ig and cinder adhere to the lin- 
ing at one point to-day and at another to-morrow, and the 
chipping-out must be dififerent. The lining is burned away 
more at one point to-day than it was yesterday. A new lining 
requires a dififerent shaping than an old one, as lining burns 
out and the diameter of the cupola increases. More fuel is re- 
quired for a bed, and the weight of charges of fuel and iron 
must be increased. All bricks are not suitable for a cupola 
lining, and a good brick may be laid up in such a way that a 
lining will not last half so long as it would do if properly put 
in. All daubing material is not suitable for repairing the hn- 
ing of a cupola, and the best daubing is worthless when not 
properly applied. Bottom sand when used over and over again 
becomes worthless, and all sands are not suitable for a bottom. 
The front may be put in with material that melts, and the tap 
hole cannot be kept open and free of slag; or the front made 
of a shape that iron chills in the tap hole between taps. The 
spout lining material may not be suitable, and may melt and 
bung up the spout with slag, or the lining may be made of a 
shape that two or three ladles are required to catch the many 
streams that fall from it at the same time. 

To learn to manage a cupola perfectly, a close study of all 
the materials used in melting and their application to melting 
is necessary, and months of careful observation are required 
to learn them, but by an intelligent man they can be learned. 
A molder, when serving his time as an apprentice, is seldom 
given an opportunity to learn melting, and when he becomes 
foreman of a foundry knows nothing whatever about the man- 
agement of a cupola and is completely at the mercy of the 



2S4 THE CUPOLA FURNACE. 

melter. The time has passed in many localities when the entire 
force employed in a foundry was subject to the whims of a 
melter and compelled to take a day off whenever he did not 
see fit to work, and a foreman who does not fully understand 
the management of cupolas is no longer considered a com- 
petent man to have charge of a foundry. It should be the aim 
of every molder who aspires to be a foreman or foundryman 
to learn melting, and when he takes charge of a foundry he 
should at once learn all the peculiarities of the cupolas of that 
foundry, and be able to run off a heat as well as the melter, or 
instruct the melter how to do it. In conversation with foremen, 
we have frequently remarked to them that the foreman of a 
foundry should be the melter, and many of them have replied 
that they would give up the foremanship before they would do 
the melting. To be a melter does not imply that the melter 
should perform the labor requisite to melting, for a melter may 
direct the melting of a heat without ever touching the iron to 
be melted or any of the material required to melt it. By going 
inside for a few minutes and giving directions how it must be 
done, any intelligent man can be employed to do the work, 
and he can be instructed from the charging door how to pick 
out and daub a cupola or repair a lining. He can be shown 
how to put up the doors and support them in place ; how to 
prepare daubing, front and spout material, select and temper 
bottom sand, and instructed from the charging door and front, 
how to put in a bottom front and spout lining; how to light 
up and burn the bed, and given a slate of charges and direc- 
tions for putting them in the cupola. After he has been 
directed by a competent melter in this way for a few heats, it is 
only necessary for the melter or instructor to inspect his work 
from time to time, to see that it is properly done and prevent 
the lining getting out of shape or other things occurring, in 
which a new melter cannot be instructed in a few days ; and his 
work should be inspected to prevent him getting into a rut, as 
melters so frequently do when left to themselves. 



ART IN MELTING. 285 

TAKING OFF THE BLAST DURING A HEAT. 

The length of time the blast can be taken off a cupola after 
it has been in blast long enough to melt iron, and put on again 
and good melting done, depends upon the condition of the 
stock in the cupola at the time it has been stopped. 

The blast may for many hours be taken off a cupola that 
has only been in blast for a short time, is in good melting con- 
dition and filled with stock, if the melted iron and slag are all 
drawn off and the tuyeres carefully closed to exclude the air 
and prevent melting and chilling after the blast has been 
stopped. We have known a cupola in this condition in case 
of a breakdown in the blowing machinery to be held from four 
o'clock in the afternoon until eight o'clock the following morn- 
ing, and good melting done when the blast was again put on. 

In this case, the tuyeres were packed with new molding sand 
rammed in solid to completely exclude the air, and the molten 
iron all drawn off, after the tuyeres had been closed for a short 
time and the tap hole closed with a bod. Before putting on 
the blast in the morning, the tuyeres were permitted to remain 
open for a short time, to allow any gas that might have collected 
in the cupola during the stoppage to escape and avoid an ex- 
plosion, which might have occurred had a large volume of blast 
been forced into the cupola when filled with gas. 

Cupolas that have been in blast for some time and from 
which the blast is removed toward the end of the heat when 
the cupola is comparatively empty, or in bad shape for melt- 
ing, cannot be held for any great length of time, even if the 
tuyeres are at once closed and every precaution taken to pre- 
vent chilling and clogging. This is due to the gradual settling 
of a semi fluid slag and cinder above the tuyeres, and the clos- 
ing up of small openings in it through which the blast was dis- 
tributed to the stock ; and in case of accident to the blower it is 
better to dump the cupola at once than to attempt to hold it 
for any length of time. 

Cupolas, in which all the iron charged has been melted and 
drawn off, may be held over night, if the cupola has been 



286 THE CUPOLA FURNACE. 

properly fluxed, the slag drawn off, and a fresh charge of coke 
put in, with a Hberal charge of Hmestone on top of it to liquefy 
any slag that may over night have chilled in the cupola. 
Small cupolas are frequently managed in this way; the tuyeres 
are closed and the tap hole permitted to remain open to admit 
sufificient air to ignite the fresh coke. 

In the morning after the cupola has been filled with stock 
and the blast put on, the limestone on the bed is the first to 
melt, and if in sufificient quantity makes a fluid slag that 
settles to the bottom, freeing the cupola of any clogging that 
may have taken place during the stoppage. 

BANKING A CUPOLA. 

Since writing the foregoing we have received the following 
practical illustration of keei)ing a cupola in good condition for 
meli-ing for many hours after it had been charged and the blast 
put on, from Mr. Knoeppcl, Foundry Superintendent, Buffalo 
Forge Co., Buffalo, N. Y. In this case melting had not begun 
before the pulley broke and the blast was taken off, but the 
same results would have been obtained from banking the 
cupola in this way if melting had begun and the cupola had 
been in blast for a short time. Mr. Knoeppel writes as follows : 

" Banking a cupola is something that does not come in the 
usual course of foundry practice, but there are times when the 
knowledge of how it is to be done would be a source of profit, 
as well as loss of time being averted. By request having been 
induced to allow this letter to appear in your valuable publica- 
tion on 'Cupola Practice;' hence will try and give you the 
details as near as I can from memory, although I wrote an arti- 
cle on this subject in the ' American Machinist,' December lO, 
1891, which I am now unable to get. 

" In the latter part of October, 1891, just as we were about 
to put on the blast in our. foundry cupola and the fan making a 
few revolutions, the main pulley broke, running the main shaft 
to the fan or blower of our cupola. After considerable trouble, 
loss of time and delay in trying to get a new pulley, which was 



ART IN MELTING. 287 

of wood pattern, we finally succeeded in getting one of the 
proper size, and had it put on the shaft ; but the belt being a 
little tight, and also anxious to get ofT the heat, in slipping the 
belt on the pulley, it was cut in such a shape that it became use- 
less for that day. By this time it was beyond our regular hour 
for quitting. At first there seemed no way out of the dilemma 
but to drop the bottom. The thought of re-handling the hot 
material and fuel, the extra labor attached therewith, suggested 
the idea of holding up the charges until next morning, when 
repairs would be completed. After a few moments' consulta- 
tion, proceeded as follows : Let me say first that the cupola 
was lighted at 1.45 p. m. and at 6 p. m began the operation 
of banking the cupola, havmg had four hours and fifteen min- 
utes' time for burning the stock, and being charged with eleven 
tons of metal. The cupola was of the Colliau type 60" shell 
lined to 44'' at bottom and 48" at melting zone, having six 
lower tuyeres, 7''x9'^ upper tuyeres being closed. Height of 
tuyeres from bottom when made up I8^^ blast pressure 10 oz., 
revolutions of blower about 2100, manufactured by the BufTalo 
Forge Co., and known as No. 10, the adjustable bed type. The 
cupola bed was made up of 600 lbs. Lehigh lump coal and 800 
lbs. Connellsville coke, the succeeding charges 50 lbs. of coal 
and 150 lbs. coke, coal being an important factor in this heat 
on account of its lasting qualities. We first cleaned and cleared 
all of the tuyeres, packed each one with new coke, and then filled 
and rammed them tight with floor moulding sand to prevent 
any draft getting through them, and had the top of charges 
covered with fine coal and coke dust, and tightened that also to 
stop the draft in that direction. The object in using coal dust 
was this : Should any get through into the charges, it would not 
cause much trouble. After all was completed, gave orders to 
the cupola men to be on hand at 6 a. m. next morning, clean 
out the tuyeres and top of cupola, and ordered the men to be 
ready for pouring ofT at 7 a. m. The next morning all were on 
time. I had the tuyeres poked with bars, so that the blast 
might have easy access to center of cupola, and started the 



288 THE CUPOLA FURNACE. 

blast at 7 : 15, bottom being dropped at 8 : 45 ; total time from 
time of lighting cupola until bottom dropped was nineteen 
hours. At first the iron was long in coming down and first 500 
lbs. somewhat dull, but made provision for that and put it into 
dies, which turned out to be very good. The balance of the 
heat was hot enough for any kind of casting — our line being 
light and heavy — and had to be planed, bored and otherwise 
finished with some stove repair casting in with this heat engine 
casting, cylinder and a class of work that requires fluid metal. 
I am confident that if this method is carefully followed, it can 
be done at all times, but would not advise it in small cupolas, 
less than 36" inside measurement; and should the melt be in 
progress, it could not be successfully done at all. Should I be 
placed in a similar position, would resort to the same means 
with more confidence and certainty of success. 
" Yours respectfully, 

" John C. Knceppel, 
" Foundry Supt. Buffalo Forge Co., Biffalo, N. V." 

GIVE THE MELTER A CHANCE. 

There is no man about a foundry for whom we have more 
respect than a practical and scientific melter. He is generally 
a self-made man and has learned the art of melting himself. 
He is a man of intelligence, who, perhaps, has been a melter's 
helper and a close observer of the work, and when given charge 
of a cupola, has followed in his footsteps or improved on the 
methods of his predecessors. He may have been a man who 
was given a few instructions in melting when he first began, and 
has become an expert through his own efforts. He is respected 
by the foreman and molders, and well-paid by his employer. 
There is no man about a foundry for whom we have more pity 
than a poor melter, for he seldom melts two heats alike, and is 
cursed by the piece molders who have lost their work through 
bad iron. Gibed by the day molders, lectured by the foreman, 
looked black at by his employer, poorly paid, and respected 
by no one about the foundry, his lot is a hard one. 



ART IN MELTING. 289 

A poor melter is not always to blame for doing poor work, 
for he may have been a foundry laborer who was put to work 
as a melter, and never given proper instruction in the manage- 
ment of a cupola. Again, a good melter may be made a poor 
one from being interfered with by others who do not under- 
stand melting. Foundrymen in conversing with each other 
learn that they are melting ten pounds of iron to the pound of 
fuel. The foundryman not being a practical man, does not 
inquire the size of the heat or cupola in which it is melted, the 
conditions under which it is melted, or the kind of work the 
iron is for. He does not stop to think that the other foundry- 
man may be lying to him, or is deceived by his melter and 
does not know how many pounds of iron he is melting to the 
pound of fuel. But he goes to his foundry and insists that iron 
must be melted at a ratio of 10 to i. The conditions in his 
foundry may be totally dififerent from those of the other one, 
and iron may not be melted at a ratio of 10 to i in the other 
foundry. The melter. if he is a practical man, knows this, or 
finds it out the first heat, and to hold his job shovels in extra 
fuel, unbeknown to any one, and if he is watched, does not get 
it in evenly or at the proper time, and the result is uneven melt- 
ing and dull iron, Foundrymen do not always furnish their 
melters with proper tools for chipping out and making up the 
cupola, a suitable material for repairing and keeping up the 
lining, a proper flux for glazing the lining and making the cu- 
pola melt and chip out free, and a man who would be a good 
melter if given a chance, is frequently made a poor one by 
being hampered in his work for want of tools and material to 
work with. He is blamed for poor melting when it is really not 
his fault. Good melters frequently get into a rut or certain 
way of doing their work, for want of text-books and other liter- 
ature on melting to read and study, or association with men of 
their calling, and become very poor melters. As a lawyer who 
does not read law-books that are up to the times and associate 
with his colleagues, becomes a pettifogger, so does a doctor 
who does not study his text- books and medical literature, diag- 
19 



290 THE CUPOLA FURNACE. 

noses all cases as one of two or three diseases, has one or two 
prescri[)tions which he prescribes for all cases. The man of 
learning, or a man who knows it all, when left to himself for 
years gets to know nothing; and so it is with melters when left 
to themselves. They forget many things they are not called 
upon to practice every day, and in time get into a rut or routine 
from which they unconsciously gradually degenerate if the mind 
is not refreshed by reading or contact with other melters. It 
should be the aim of every melter to converse with other 
melters upon cupola matters at every opportunity, and to read 
and study all literature upon the subject, whether good or bad ; 
for, if good, he. may learn something new, and, if bad, it stimu- 
lates the mind to reason why it is not good, and how it can be 
improved upon. It recalls to mind facts in his own experience 
which have long been forgotten, and he learns something, at all 
events. It is to the interest of every foundrymen who depends 
upon his melter for results to keep him posted upon all that is 
new in the business, and he should furnish him all the new lit- 
erature on the subject that comes into his office or is published. 



CHAPTER XVI. 



THE CUPOLA ACCOUNTS. 



In all well regulated foundries a cupola account of melting 
is kept and an accurate record made of each heat, and pre- 
served for future reference. In this way, the melting is re- 
duced to a system and the foundryman knows what is being 
■done in his cupola each day and is able to make an estimate 
of the cost of melting. These records are also of value in 
showing the amount of fuel required for a bed and in charges 
when the cupola is newly lined, and the amount they should be 
increased as the lining burns out and the cupola is enlarged. 
Mixtures of various brands and grades of iron are recorded, 
with the result of the mixtures upon the quality of castings, and 
a great deal of experimental work in melting and mixing of 
irons is saved and better results are thus obtained. The 
manner of keeping these accounts varies in dififerent foundries. 
In some they are kept very simply, showing only the amount 
of fuel and iron in each charge and total fuel consumed, iron 
melted, and time required in melting. Others show kind and 
amount of fuel used, in bed and charges, and amount of each 
brand or quality of iron placed in charges, total amount 
melted, time of lighting up, time of charging, putting on blast, 
first iron melted, blast off, pressure of blast, etc. 

Others are still more elaborate, and not only show all the de- 
tails of the cupola management, but also a report presenting 
cost of various castings produced, good and bad, the cost of 
the bad ones being charged to the good ones made of the 
same pattern or for the same order, and the average found. 

To give foundrymen who have never used such reports an 
idea of how they are made out, we here give a few blank re- 
port from leading foundries. Those of Abendroth Brothers, 
Port Chester, N, Y., and of Byram & Co., are filled in to show 
the manner of placing the various items in the blank report. 

(291 ) 



292 



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THE CUPOLA ACCOUNTS. 

BYRAM & COMPANY, 

IRON WORKS. 



293 



435 and 437 Guoin Street. 
46 and 48 Wight Street. 



DETROIT, MICH. 



FUEL USED and IRON MELTED at the Foundry of 



IN THE COLLIAU CUPOLA 
FURNACE. 



.Size. 



Diameter Inside of Lining 54 ins. 

Pressure of Blast ... .ozs. 



Lighting, 

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■Closed Tap Hole, - 

First Iron Taken, - 

Loading Finished, - 

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No. 



294 



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Cupola Slate for Charging and Cupola Report. 



J97 



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298 THE CUPOLA FURNACE, 

The blanks for these reports and records of them are fur- 
nished to the foundry foreman or melter, and preserved in dif- 
ferent ways. In some foundries they are furnished in separate 
sheets, and when filled out and returned are kept in files pro- 
vided for the purpose. In other foundries they are made out 
in book form and filled in by the foreman or foundry clerk. 
Such reports can be kept by a foundry foreman when provided 
with a small oflSce for doing such work; but when there is no 
office, as is frequently the case, a report book kept by the fore- 
man soon becomes so soiled that it is useless for reference, and 
report blanks are generally furnished in separate sheets and 
either filed or transferred to the report book by the foundry 
clerk. When only a record of fuel used and iron melted is kept, 
the report is generally made on a slate upon which lines are 
scratched similar to those in a printed report, and name and 
amount of various grades of iron and fuel filled in with the 
slate pencil. The fuel to be used and amounts of various irons 
to be melted in each charge are placed upon the slate by the 
foreman and given to the melter to charge the cupola by, and 
after the heat is melted the slate is sent to the foundry ofifice to 
be copied into the cupola account book. This latter is the 
oldest way of making out these reports. 

A cupola account is of no value if not correctly kept, and it 
should be the aim of every foundry foreman to see that the re- 
port he makes of fuel consumed and iron melted is correct, and 
not, as is frequently done, endeavor to make a good showing 
for himself, of melting a large per cent, of iron with a small per 
cent, of fuel, and permit his melter to shovel in extra fuel to 
make iron sufficiently hot to run the work. Foundrymen can 
readily ascertain the amount of fuel consumed by comparing 
the amount reported with the amount purchased. False re- 
ports only reduce the foreman in the estimation of his employ- 
ers, and are frequently the cause of him losing his position. 

COST OF MELTING. 

There is probably less known about the actual cost of melt- 



THE CUPOLA ACCOUNTS. 299 

ing iron in cupolas for foundry work than about any other 
branch of the foundry business. But few foundrymen make 
any attempt at keeping a cupola or melting account. Many of 
those who do, keep it in such a way that they not only fail to 
learn the cost of melting, but are misled by the account to 
suppose their melting costs them a great deal less per ton than 
it really does. In the majority of foundries the melting is left 
entirely in the hands of the melter, who as a rule has no system 
for doing the work, and has no control over his assistants, or 
interest in having them do a fair day's work. In many of the 
foundries we visit, twice the number of man are employed as 
cupolamen as are employed in melting the same amount of iron 
in other foundries, where the facilities for handling the stock 
are almost the same; and the expense of lining and daubing 
material is frequently double with one melter what it is with 
another in the same sized cupola with the same sized heats. 

In many foundries the fuel is not weighed, but is measured 
in baskets, or the number of shovelfuls counted and the weight 
estimated. When the fuel is measured in baskets, the baskets 
always stretch and enlarge, and an old basket frequently holds 
one-third more than a new one; from 10 to 20 pounds more 
can easily be piled on the top of a basket after it is filled. 
Foundrymen who charge their fuel by the basket always use 
more of it than they estimate they are using; when the shovel- 
fuls are counted, each shovelful may be made to weigh more than 
is estimated, and a few extra shovelfuls are always thrown in, 
for fear some were not full. When too much fuel is used in a 
cupola there is not only a wastage of it, but there is slow melt- 
ing, increased destruction of the lining, and an increased wear 
and tear of the blast machinery. For these reasons every 
pound of fuel that goes into the cupola should be accurately 
weighed. Even when it is supposed to be accurately weighed, 
there should be some check on the melter, for he will shovel in 
extra fuel if not watched. 

At a foundry we recently visited in New Jersey a supposed 
accurate account of the melting had been kept for a year ; at the 



300 THE CUPOLA FURNACE. 

end of the year the president of the company had figured up 
the amount of fuel consumed in the cupola and compared it 
with the amount purchased, and found they were short 260 
tons. At another foundry, where the melter always reported 
melting 7 pounds of iron to i pound of anthracite coal, they 
ran short 300 tons in a year. This kind of work should be 
prevented by checking up the melter's report and comparing it 
with each car-load of fuel consumed. 

A cupola book should be provided, with blank spaces for re- 
cording the weight of coal or coke in the bed and charges, and 
the weight of each brand of iron, No. i, 2 or 3 and scrap, show- 
ing the exact mixture of each charge and heat. A note should 
also be made of the quality of iron produced from the mixture. 
Such a record is of great value in making mixtures and charg- 
ing a cupola, if it is properly kept. 

The cost of melting per ton is figured in a number of differ- 
ent ways, but to be of any practical value the entire cost of 
melting should be figured on as follows: 

Interest on cost of cupola plant and depreciation in value of 
same. 

Fire brick for relining and repairs. 

Fire clay, loam and sand for cupolas and ladles. 

Repairs to cupola, blast pipe, elevator, scaffold, runway, 
iDlower, &c. 

Belts, oil, &c., for blower. 

One fourth the entire cost of engine. 

Tools, wheelbarrows, buckets, hose, shovels, forks, rakes, 
hoes, sledges, picks, bars, trowels, bod sticks, tap bars, &c. 

Wood for lighting up and drying ladles. 

Coal or coke consumed in melting. 

Labor employed in removing the dump, making up cupola, 
milling dump and gates, collecting gates, scrap and bad cast- 
ing from foundry, placing iron and fuel on scaffold, charging, 
breaking and piling iron in yard, breaking up bad castings, 
daubing ladles, &c. 

When the cost of all these items has been learned, and the 



THE CUPOLA ACCOUNTS. JO I 

amount divided by the number of tons melted, it will be found 
tliat the cost of melting is about $2 per net ton of iron in the 
ladles. In foundries with all the modern improvements for 
handling the stock the cost is a little less than $2 per ton, and 
in foundries with none of the improvements for handling the 
stock and no system in melting, the cost per ton is as high as 
$3. When there is doubt as to the accuracy of weights in 
charging, the weights should be compared with the fuel pur- 
chased and castings sold, and the cost of melting may be 
figured on the weight of castings sold in the place of the 
amount of iron melted. To make a cupola report of value, 
the fuel, labor and tool accounts should be kept separate, and 
an efitbrt made to reduce the expense of each account. 



CHAPTER XVII. 

EXPLOSION OF MOLTEN IRON. 

Molten iron is a very explosive body, and under certain 
conditions explodes with as loud a report and as much vio- 
lence as gunpowder. Under other conditions it is not at all 
explosive, but those under which it explodes must be fully un- 
derstood and avoided by melters and moulders to prevent dan- 
gerous accidents. 

A stream of iron flows from a tap-hole and spout smoothly 
if the front and spout lining have been properly dried. When 
wet the iron explodes as it emerges from the tap-hole, and is 
thrown in small particles some distance from the cupola. The 
instant a stream of iron strikes a wet spout it explodes and the 
entire stream is thrown from the spout in all directions with 
great force. In a damp spout the iron boils and small particles 
may be thrown ofT, but the explosion is not so violent as from 
a wet spout. 

A wet bod causes molten iron to explode the instant it 
comes in contact with the stream, and it is impossible to close 
a tap-hole with it. A bod containing a little too much moist- 
ure causes a less violent explosion and a tap hole may be 
closed with it, but in closing it, the iron explodes and is fre- 
quently thrown from the tap-hole with great force past the sides 
of the bod before the latter is pressed into the hole. When the 
bod is in place in the hole one or more small explosions fre- 
quently take place, and the bod-stick must be firmly held 
against the bod to prevent it being blown out. The kick or 
thump felt against the end of a bod- stick when pressing a bod 
into place is due to these explosions, and not to the pressure 
of molten iron in the cupola, as is generally supposed. Bod 

( 302 ) 



EXPLOSION OF MOLTEN IRON. 303 

material should be no wetter than molding sand properly tem- 
pered for molding. 

When the iron is very hard, a stream of it when very hot throws 
ofif a great many sparks from a dry spout. These sparks are 
caused by an explosion of the iron due to the combination of 
oxygen with the combined carbon of the iron, and the sparks 
are the oxide of iron. They contain very little heat, and melt- 
ers or molders do not hesitate to enter showers of these sparks 
to stop in or catch the stream of iron. The sparks from explo- 
sions caused by dampness are of an entirely different character, 
and burn the flesh or clothing wherever they strike. 

A wet, cold or rusted tapping bar thrust into a stream of 
iron in the tap-hole or spout, causes the iron to explode. Tap 
bars should, therefore, always be heated before they are put 
into the stream of iron. 

When iron falls from a spout upon a hard floor, it spatters 
and flies in small particles to a considerable distance from the 
place it first strikes, and it is dangerous to go near the spout 
as long as the stream is falling upon the floor. 

When iron falls from a spout upon a wet, muddy floor, it ex- 
plodes instantly, and small particles of molten iron may thus 
be thrown a hundred feet from the cupola. If the stream con- 
tinues to run upon the floor, one explosion follows another in 
rapid succession, or a pool of molten iron is formed, which 
boils and explodes every few minutes, as long as there is any 
moisture in the floor and the iron remains liquid. The floor 
under a spout should always be made of loose dry sand, with 
a hole in it to catch any iron that falls from the spout. 

The floor under a cupola should always be dry, and when 
paved with brick or stone, should be covered with an inch or 
two of dry sand before dumping, to prevent fluid iron or slag 
in the bottom of the cupola spattering or exploding when 
dumped. 

Molten iron explodes violently when a piece of cold, wet or 
rusted iron is thrust suddenly into it, as the writer has reason 
to know from practical experience, when working at stove 



304 THE CUPOLA FURNACE. 

moulding in the winter of 1866 and 1867. Knowing that a 
rusty or wet skimmer made iron explode, we always took the 
precaution of putting our skimmers into the foundry heating 
stove and heating them to a red heat before catching iron. 
One day we had taken this precaution, heating a skimmer to a 
red heat and putting it in a convenient place for use. A small 
boy who was around the foundry and sometimes skimmed our 
iron before pouring, saw the red-hot skimmer, and took it out 
and put it in the snow while we were catching a ladle of iron. 
As soon as we set the ladle on the floor he ran in with the 
skimmer dripping wet, and before we could prevent him, thrust 
into the molten iron. The iron exploded instantly and was 
thrown all over us as we leaned over the ladle, burning us so 
severely that we were not able to be out of the house for sev- 
eral weeks, and we still carry the scars from those burns. The 
iron was thrown with great violence, and passed through our 
clothing and a thick felt hat, like shot from a gun. The 
exploded iron passed over the boy's head and he was burned 
slightly, but never was seen about the foundry again, and prob- 
ably never became an iron moulder. 

Molten iron when poured into a damp or rusted chill-mould 
or a wet sand-mould, explodes and is thrown from the mould 
and escaping from a mould upon a wet floor or into the bot- 
tom of a wet pit, explodes. In the foundry of Wm. McGilvery 
& Company, Sharon, Pa., a deep pit for casting rolls on end 
was put in the foundry floor and lined with boiler plate. The 
first roll cast in this pit was one eleven feet long, weighing 
about five tons, moulded in a flask constructed in ring sections 
and clamped together. The mould was not properly made and 
clamped, and when almost filled with molten iron gave way 
near the bottom and permitted the iron to escape into the pit, 
the bottom of which was covered with wet sand ot mud. The 
iron at once exploded and forced its way up through ten feet 
of sand that had been rammed about the mould in the pit, and 
was thrown up to the foundry roof at a height of forty feet. 
The molten iron continued to explode until nearly four tons 



EXPLOSION OF MOLTEN IRON. 305 

were thrown from the pit in small particles, and the foundry 
burned to the ground. 

Molten iron explodes when poured into mud or brought in 
contact with wet rusted scrap, but does not explode when 
poured into deep or clean water. At a small foundry that 
stood near the Pittsburg & Erie canal, in Sharon, Pa., many 
years ago, a wager was made by two moulders that molten 
iron could not be poured into the water of the canal without 
exploding. A ladle of iron was accordingly taken to the canal 
and poured into the water without any explosion taking place. 
A few days later an apprentice boy who had witnessed the ex- 
periment undertook to pour some into water in an old salt ket- 
tle that sat in the yard near the foundry and contained rusted 
scrap and mud under the water. An explosion at once took 
place that almost wrecked the foundry. The water in this 
case was not of sufficient depth to destroy the explosive pro- 
perty of the molten metal before it came in contact with the 
rusted scrap and mud at the bottom of the kettle. 

Moulders frequently pour the little iron they have left over, 
after pouring off their day's work, into a bucket of water to 
heat the water for washing in cold weather. This was a com- 
mon practice of the moulders in the foundry of James Mar'^h, 
Lewisburg, Pa., until one day iron was poured into a bucket of 
water in which clay wash had been mixed and contained mud 
at the bottom. It exploded instantly with so great a violence 
that all the windows were blown out of the foundry, and this 
stopped the heating of water for washing, in that way, at that 
foundry. 

At another foundry, iron poured into clear water in a rusted 
cast-iron pot, exploded, doing great damage. 

At the foundry of North Bros., Philadelphia, Pa., during the 
flood in the Schuylkill river, June, 1895, the cupola was pre- 
pared for a heat and the blast put on ; but before the heat could 
be poured ofif water soaked into the cupola pit and had to be 
bailed out to prevent the pit being filled. The heat was all 
poured before water came upon the moulding floors, but the 
20 



306 THE CUPOLA FURNACE. 

bottom of the cupola pit was soaking wet, and the melter, in his 
eagerness to leave the foundry before it was flooded, dropped 
the bottom without drawing off the molten iron remaining in 
the cupola. The instant the molten iron and slag dumped from 
the cupola came in contact with the wet floor of the pit, a 
violent explosion took place, scattering molten iron, slag and 
fuel in all directions and blowing all the windows out of the 
foundry. Had the melter taken the precaution to have drawn 
ofif all the molten iron before dumping, and thrown a few 
shovelfuls of dry sand under the cupola to receive the first 
slag to fall upon the bottom, this explosion would not have 
taken place. 

At the foundry of The Skinn?r Engine Co., Erie, Pa., a vio- 
lent explosion took place in their cupola which almost entirely 
wrecked it. At the time of this explosion, a lot of small 
steam cylinders were being melted in the cupola, and in some 
of these cylinders the ports of the steam chest had been closed 
by rust, leaving the steam-chest filled with water, from which 
it could not escape. The foreman, David Smith, had given 
the melter orders to see that each of these cylinders was 
broken before being put into the cupola, but this order had by 
the melter been disregarded, and the explosion was attributed 
to the water confined in one of the cylinders being converted 
into steam and exploding with such violence as to wreck the 
cupola. 

At the foundry of The Bufifalo School Furniture Co., Buffalo, 
N. Y., an explosion took place in 1895 in their sixty-inch 
cupola, about seven minutes after the blast was put on for a 
heat, which blew the heavy cast-iron door from the tuyere box, 
on each side of the cupola; and also blew out the front and 
broke the heavy cast-iron bottom doors. A number of men 
who chanced to be near the cupola were severely burned, but 
fortunately none were killed. This explosion was attributed to 
a number of causes, one of which was the formation of gas in 
the cupola before the blast was put on, which was exploded by 
the addition of oxygen from the blast. But this could hardl)' 



EXPLOSION OF MOLTEN IRON. 307 

have been the cause, for the blast had been on fully seven 
minutes before the explosion occurred, and had this been the 
cause the explosion would have taken place almost as soon as 
the blast was put on. Another cause given for the explosion 
was that dynamite had been placed in the cupola concealed in 
some pieces of scrap-iron. This may have been the case, or 
some other explosive body may have been concealed in the 
scrap; but it is just as probable that it was due to steam 
generated from water confined in some piece of the scrap, 
by rusting of the opening through which it was admitted to 
the casting ; as in the case at the foundry of The Skinner 
Engine Co. 

A damp ladle causes iron to boil, and if the daubing is very 
thick may cause it to explode. A wet daubing or water in a 
ladle explodes the iron the instant it touches it. Wet or rusted 
scrap-iron placed in a ladle to chill the molten iron, causes the 
iron, if tapped upon it, or if thrown into a ladle of iron, to ex- 
plode. Such an explosion may be prevented by heating the 
scrap to a red heat just before using it to chill the iron. 



CHAPTER XVIII. 

GETTING UP CUPOLA STOCK. 

Probably the oldest and original way of placing stock upon 
a cupola scaffold is to lift or throw it up by hand from one plat- 
form to another until placed upon the scaffold. This appears 
to have been the only means of getting up the stock in the early 
days of foundry practice in this country, and this method is 
still practiced in many small foundries. A platform four or 
five feet square and probably five feet high, is constructed 
alongside the scaffold and fuel and iron are thrown upon it, 
until it is filled. The mclter then gets upon the platform, and 
throws the material from this upon another platform from which 
he again throws it upon the cupola scaffold. When the cupola 
is low, one platform is suflficient, and in a small foundry recently 
visited, we observed that the scaffold had been entirely dis- 
pensed with, and fuel and iron were thrown from the platform 
directly into the charging door of the cupola at a height of 
probably five feet above the platform. This method of getting 
up cupola stock answers very well for small cupolas melting a 
few hundredweight of iron, two or three times a week, and for 
small foundries with limited room is probably the cheapest and 
most practical method that can be devised for the plant. 

WHEELBARROW RUNWAYS. 

An improvement upon the above method is the runway or 
inclined plane constructed for wheeling up stock upon wheel- 
barrows. This method, which is much in use in foundries 
melting small heats, requires less handling of the stock and the 
latter may be placed upon the scaffold more rapidly and with 
less labor, but it requires more room than the platform, for the 

( 308 ) 



GETTING UP CUPOLA STOCK. 309 

runway has to be made long to give a grade upon which a 
good load may be pushed up on a wheelbarrow. 

When there is not sufficient room for a long runway, or in 
case it should terminate too far from the stock yard, it is in 
many plants so arranged that it runs half-way up to a platform 
and then makes a turn in the opposite or another direction to 
the scafifold. When runways are steep cleats have to be nailed 
upon them to insure a good footing, and an additional man is 
frequently required to pull the barrow with a rope in getting 
up a load, while with a proper runway, many cupola men wheel 
up 500 weight of pig with apparent ease. But these are experts 
and the average load is much lighter on the best of runways. 

TRACK RUNWAYS. 

A track runway is one as above described upon which a 
track is placed and a small car is drawn up by a chain rope 
or wire cable. This method replaced the barrow runway in 
many of the larger foundries years ago, and had the advantage 
of getting up stock more rapidly and with less outlay for labor. 
Many of these runways were very complete in design and con- 
struction with tracks extending to various parts of the yard 
upon which the cars were run to convey iron and fuel to the 
cupola with the least possible amount of labor in handling. 
This system is a good one and, if properly constructed with a 
good roadbed and steel rails in the yard, greatly facilitates the 
handling of iron from the various piles used in the mixture. A 
horse may be used in the yard for drawing the cars to the run- 
way, and if a sufficient number of cars is provided, the mixture 
of iron may be made when loading and the cars unloaded 
directly into the cupola; but when not properly designed and 
constructed the machinery gets out of order, rope breaks, cars 
jump the track, etc., making it the worst system that can be 
adopted. 

ELEVATORS. 

Since the perfecting of design and construction of elevators 
to a point where they may be run by almost any person with- 



3IO THE CUPOLA FURNACE. 

out constantly being put out of order by sudden throwing on 
or off of power, overloading, lack of care, etc., they have almost 
entirely replaced all the methods before desciibed for the get- 
ting up of cupola stock. The elevator as a stock lifter presents 
the following advantages : It takes up very little room, may be 
placed at the most convenient point for unloading stock, lifts 
stock rapidly to the scaffold, saves time and labor; it may be 
used with wheelbarrows, trucks or car and a yard-track system. 
For these reasons they have them installed in almost every 
foundry plant of sufficient size to warrant their use where stock 
has to be elevated to place it upon the scaffold. There are a 
large number of makes of elevators upon the market, but for 
cupola work many of them are entirely too light, too delicate in 
construction, and easily put out of order by overloading, im- 
proper handling, dirt and neglect. On the other hand, there 
are a number of elevators upon the market especially designed 
for this work, and only these should be installed. Among the 
best of these we have seen in operation are those of The Craig 
Ridgway & Son Co., of the merits of which they have the fol- 
lowing to say : 

" The Steam-Hydraulic Elevator. Goes by steam or com- 
pressed air — steam always to be preferred. No machine ever 
introduced has met with such instant favor as this elevator. 
Hundreds are being placed in the best establishments all over 
the land. It is the most perfect of hydraulic elevators without 
the use of a pump, by simply running a small steam pipe to 
the nearest boiler. These elevators are rapid and do the work 
while other elevators are getting started. How perfect the 
motion is can be judged from the fact that we use the same 
system in foundry cranes for handling great ladles of molten 
iron and steel where the least irregularity of action would mean 
death to men and destruction to property. One of the most 
remarkable features of this elevator is the fact that it never gets 
out of order. Nothing puts it out of service but the boiler 
blowing up. When the boiler " lets go " no other elevator will 
be required ! 



GETTING UP CUPOLA STOCK. 



311 



" The cuts, Figs. 55 and 56 show the two most popular styles 
of the steam hydraulic elevator. 

" The Double Geared. — In this style all machinery is above 
ground. The frame is easily and cheaply made of wood by any 
carpenter, or, if desired, will be furnished by us. The cage has 
safety catches, but the best safety is the two or three separate 
lifting ropes. Everything is made heavy and substantial to 



Fig. 5 c 




Fig. 56. 




DIRFXT ACTING. 



DOUBLE GEARED. 



Stand hard work and bad usage. Hundreds of this type are in 
daily service. 

" The Direct Acting. — In this style a well is required. This is 
dug in the old-fashioned manner by the local well digger and 
walled up dry. When the water cylinder is placed upon the 
upper floor the head of water partly counterbalances ram and 
platform. The water cylinder can be placed anywhere. Note 
the long guides upon platform and the heavy under-bracing. 
This elevator is simple and easy of erection, and great numbers 
of them are in dail)' operation all over the land." 

LiniNG MAGNETS. 

The latest device for placing iron upon a cupola scaffold is 
the lifting magnet of the Electric Controller & Supply Co., an 



312 



THE CUPOLA FURNACE. 



idea of which may be gained from the illustration, fig. 57, in 
which the magnet is the small round device attached to the 




hook of the crane, and to the under side of which are attached 
pieces of scrap iron lifted by the magnet from the pile below. 



GETTING UP CUPOLA STOCK. 313 

The magnet is complete in itself and may be attached for use 
to any traveling or swinging crane, over-head track system, etc., 
and used for lifting, moving or carrying iron as desired. The 
illustration shows a jib or swinging crane with magnet attached 
in use at the Baldwin Locomotive Works, Eddystone, Pa., for 
unloading cars of pig iron or scrap and placing it upon the 
scaffold or in the yard as desired. By this means a 30ton car 
of pig or scrap may be placed upon the scaffold in thirty min- 
utes without other labor than that of the crane-man being re- 
quired. In the same way, pig or scrap may be piled in the 
yard or lifted from any part of the yard within the swing of the 
crane and placed upon the scaffold. Iron trucks or cars with 
their loads may also be lifted from the tracks in the yard and 
placed upon a track on the scaffold, thus admitting of the de- 
sired mixture of iron being made from stock in the yard not 
within reach of the crane. The magnet may also be used for 
breaking up scrap by means of a drop weight, and for this 
purpose is said to be more effective than the old-fashioned 
hook for releasing the weight, the jerking of which frequently 
destroys the aim of the weight, resulting in failure to break the 
scrap as desired. The magnet system is thus the very cheap- 
est and quickest method that can be devised for handling 
cupola iron in plants melting large quantities of it. But at the 
present time the expense of installing this system is rather 
high for small foundries melting only a few tons of iron per day. 
This expense will no doubt be considerably reduced as the 
magnet system becomes more fully developed. 

ELEVATED STOCK YARDS. 

There are many foundries located near a hill or other high 
ground upon which their stock yards are placed upon a level 
with the cupola scaffold, so that it is only necessary to con- 
struct a barrow or track runway from the yard to the scaffold. 
One of the best arranged stock yards of this kind we have seen 
is that of the Brown & Sharpe Manufacturing Co., Providence, 
R. I. At this plant, which is located near a hill, a number of 



314 THE CUPOLA FURNACE. 

Stone arched sand bins have been constructed alongside of the 
foundry, in which all the various grades of sand used are stored. 
The floors of the sand bins are on a level with the foundry 
moulding floor, placing moulding sand, core sand and cupola 
clay right at the foundry door. The top of the bins are on a 
level with the cupola scaffold and only a few feet from it. A 
driveway on the top of the bins admits of sand and clay being 
dumped into them from the top, and iron being piled in the 
yard back of the bins. A track system on top of the bins 
extends to the cupola, and a sufficient number of cars are pro- 
vided to admit of unloading fuel and iron directly into the 
cupola, thus reducing the amount of labor required to a mini- 
mum. The whole system is under roof, making this one of the 
most convenient and inexpensive methods of getting stock upon 
a scaffold and sand into a foundry that could be devised. 

There are many foundries in this country so situated that a 
system similar to this one could be readily installed at a very 
moderate outlay, and a great saving for machinery, power and 
labor effected in the handling of cupola stock, moulding sand^ 
core sand, cupola clay, facings, etc. 



CHAPTER XIX. 

RUNNING A CONTINUOUS STREAM. 

FOUNDRYMEN are realizing more and more each year the 
importance of running a continuous stream of iron from their 
cupolas instead of stopping in and tapping out. This method 
has the advantage over the latter system of giving a hotter iron 
and one of a more even temperature. Keeps the cupola in 
better condition for melting. Admits of tuyeres being placed 
low and saving fuel in the bed, and the slagging of a cupola 
being placed under better control. But the method of handling 
iron in many foundries has not admitted of this system being 
adopted. 

To overcome this difficulty a number of devices have been 
introduced that admit of ladles being removed and replaced 
without the necessity of stopping in a stream of iron. Among 
the best of these devices are the following: 

DOUBLE SPOUT. 

Probably the oldest device of this kind is that of the Osborne 
Mower and Reaper Co., Auburn, N. Y. At this plant the 
cupola spout is made long and divided in the center by an iron 
partition, in which provisions are made for a tap hole. The 
end of the spout next to the cupola is made two or three times 
the depth and width of the ordinary spout, and a lip or spout 
placed upon the side for running off slag. The tap hole in the 
cupola is made large and the slag permitted to flow into this 
spout with the iron, from which it is run ofT at the side. This 
insures a hot, fluid slag and keeps the cupola free of slag. 
The spout will hold from one to two hundredweights of iron 
when stopped in, and when it becomes necessary to stop in to 
change ladles, it is done in a partition of the spout. This sys- 

( 315) 



3l6 THE CUPOLA FURNACE. 

tern admits of stopping in for a few minutes and holding iron 
in the spout while changing ladles, and also insures a hot, fluid 
slag, keeps the cupola free from slag, and a low-tuyere system 
may be used. 

BASIN SPOUT. 

The basin spout is a broad, basin-shaped spout, resembling 
in shape the half of a pear, the wide part forming the basin and 
the narrow part, or neck, the spout. This spout is separate 
from the regular cupola spout, and is placed under it in such a 
way that it forms a continuation of it. The basin spout is pro- 
vided with a lug or swivel, on each side near the center, by 
which it is hung upon the cupola spout. A device for raising 
or lowering the back end of the spout by means of a lever is 
also provided. When raised, it forms a continuation of the 
cupola spout, and no iron remains in it. When lowered it 
forms a basin in which 50 to 100 lbs. of iron may be held while 
ladles are being changed, and when raised, the iron in the 
basin is instantly dumped into the ladle. This device places 
the stream under the control of the tapper for a few minutes at 
a time, and is one of the best in use for small bull and hand 
ladle work, as the iron may be held in it while ladles are being 
changed, and also in case hand-ladle men are not up in time 
to catch the stream of iron. 

CROSS spour. 
This is a spout attached to the end of a cupola spout by 
means of a swivel on the under side that admits of its being 
turned to throw the stream into a ladle on either side. This 
spout has been in use at the foundry of The Lobdell Car 
Wheel Co., Wilmington, Del., for a number of years. At this 
plant it is made about four feet long and used to throw the 
stream into a five-ton ladle on either side of the cupola spout. 
When one ladle is filled the cross spout is reversed to throw 
the stream into the other ladle. In this way a heat of one 
hundred tons of iron for car wheels is drawn from the cupola 
daily without once stopping in. This company also has a very 



RUNNING A CONTINUOUS STREAM. 317 

neat method of disposing of their slag. The cupola spout, 
which is a long one, is divided in the center by an iron parti- 
tion, under which the iron flows. The cupola tapping-hole is 
made large and the slag permitted to flow out with the iron, 
and is caught by the partition in the spout. From the spout 
it is run off at a side spout and falls into a box constructed of 
iron plates clamped together. This box prevents the slag run- 
ning over the foundry floor and forms it into a solid lump 

Fig. r,8. 



S ■ 


S3Sli^^^* ' 


i 


f ■ 


^^^H|^^^^ ^H 


■ .■'^:^^W^"'^:^'^C- :{■"■■ "' 



from which it is only necessary to knock off the clamps when 
cold and remove the plate. It then may be readily broken up 
and removed from the foundry without making any dust or 
dirt as is corrimonly the case when removing hot slag from the 
floor. With the cross spout and this arrangement for slagging 
no attention need be given to either the iron or slag tap-hole 
from the beginning or to the end of the heat. And there is no 
hot slag to be cooled and removed during a heat. 



3i8 



THE CUPOLA P^URNACE. 



The cross spout may be used for a variety of purposes, and 
has recently been adopted by The Moyer Tramrail Co. for fill- 
ing tramrail ladles, as seen in the illustration, fig. 58, in which 
one ladle is being filled and a man stands ready to reverse the 
spout to fill the other one. The ladles are run to the cupola 
on a tramway loop that admits of them being run in either 
direction to the main line tramrail. 

This spout does not admit of iron being held in it in case of 
ladles not being in place to be filled, but it admits of large 
ladles being placed and the crane used for other purposes 
while one ladle is being filled. 



SPOUT LADLE. 



The spout ladle is probably the latest device for handling a 
continuous stream, and for many lines of casting the best one. 
This is an ordinary ladle of the bull type with a spout extend- 

FiG. 59. 



I 







.<rv . X > V X > ^, yx .^ >« x.\ ^ X , ^X %.^\mV^>\X\\\\\\>^ 



ing out on a line with the bottom as shown in Figs. 59 and 60. 
This spout is inclosed with a caisson of iron, the same as that 
of the ladle, and daubed to give an opening of four to six 
inches inside diameter. When placed in a position shown in 
I^ig- 59 it forms a continuation of the cupola spout, which may 
be given any desired pitch, by tipping the ladle. When it is 
desired to hold the stream while ladles are being changed, the 



RUNNING A CONTINUOUS STREAM. 



319 



ladle is tipped back as shown in Fig. 60. In this position it 
may be made to hold the stream for a minute or two while 
ladles are being changed. Or it may be filled to the dotted 
line before it becomes necessary to stop in, the stream of iron 
continually flowing through the ladle keeps it hot, and when 
tipped back the iron is not chilled by the ladle. When it is 
desired to fill the ladle from the spout ladle when it is full or 
partly full, the large opening in the spout admits of the iron 
being dumped from it very rapidly and the ladle filled at once. 



Fig. 60. 




The spout ladle may be constructed of a size to suit the ladles 
to be filled or the amount of iron that may be necessary to 
hold while waiting for a ladle. It may be mounted upon a 
permanent frame with gear for turning, or be placed upon a 
trestle to be turned by hand, and removed when it is desired 
to fill a large ladle direct from a cupola. 

This ladle was designed at the plant of The Brown-Sharpe 
Manufacturing Co., Providence, R. I., where it has been in use 
for several years in filling tramrail ladles holding about 800 lbs. 
of iron, and also other ladles of various sizes. The spout ladle 
in use at this plant holds 1200 lbs. when tipped back, and is 



320 



THE CUPOLA FURNACE. 



geared for turning. Its use has proven very satisfactory in this 
plant. 

RESERVOIR SPOUT LADLE. 

In Fig. 6i is shown the J. W. Paxson Co. Reservoir Ladle, 
mounted upon an iron frame, and geared for turning. De- 
signed for holding iron in changing ladles, as the one just de- 
scribed, forming a continViation of the cupola spout in filling 
ladles, or giving a bottom tap for skimming, by drawing the 

Fig. 6i. 









■ --^^-^ 


f 




■^ *.'>. 




I 


1^ 


/ 


^-^*^ 




p 





molten iron from beneath the dirt and slag which has risen to 
the surface of the metal. The ladle is lipped for pouring from 
the top, and may be used either for bottom or top pouring by 
closing or opening the spout tap-hole in side of ladle. The 
following table gives the capacity in pounds and price of various 
sized ladles. 



Capacity in pounds. 
Price. ... 



looo 1 200 



1500 1800 2000 2500 3000 



50' 52 00 56 00 58 65 61 25' 68 00 66 50 



Capacity in pounds. 
Price 



3500 
^82 95 



4000 
89 25 



4500 



5000 1 6000 8coo 



10,000 



95 65 102 00:119 00 132 50 162 50 



RUNNING A CONTINUOUS STREAM. 32 1 

The capacity of these ladles when tipped back to hold iron 
when changing ladles is one-half that given above. When the 
ladle is to be used only for holding iron when changing ladles, 
this fact should be stated when ordering, so that the spout 
opening may be made large to admit of ladles being rapidly 
filled from it. 

Attention has recently been called in the foundry journals to 
the Reservoir Cupola, and illustrated elsewhere in this work 
and used in connection with the Baillot Cupola, also described 
in this work. This ladle may be used to form a most perfectl)' 
designed reservoir yet constructed; it can be employed for 
holding iron in slow-melting cupolas, and the iron kept hotter 
than in the cupola, while the slag may be permitted to flow 
from the cupola with the stream, and protect the iron from the 
atmosphere, both in the spout and ladle, and the excess of slag 
permitted to flow off at the lip at the backside of the ladle. 
When not desired to use a reservoir cupola, the ladle may be 
readily removed and the cupola made an ordinary one. 

TAPPING LADLE. 

Beside the new or comparatively new devices for running a 
continuous stream, we have the old-fashioned broad-mouth 
shallow tapping ladle, from which iron may be poured while 
the stream from the cupola is falling into it. This system has 
its advantages, for the iron may be skimmed in the tapping 
ladle before filling the pouring ladles. The temperature of the 
iron may be seen and the fact determined whether it is hot 
enough to run certain work before filling the ladle for this 
work. Little drops of iron left in ladles may be poured into 
the tapping ladle in place of the pig bed. 

On the other hand, it has the disadvantage of exposing a 
large surface of iron to the cooling action of the atmosphere, 
and always retaining more or less iron, which can only be 
emptied by stopping-in. But when the cupola is running a 
good-sized stream of hot iron, the iron seldom becomes dull in 
the short time it is necessary to hold it, and this ladle answers 
the purpose for which it is used very well. 
21 



322 THE CUPOLA FURNACE. 

With any of these devices, and the blast regulated to make 
the cupola melt a stream suited to the number of ladles in use, 
a continuous stream may be run from the cupola for any sized 
heat that it may be necessar)' to melt. The running of a con- 
tinuous stream from a cupola greatly reduces the liability of 
men being burned by iron sputtering and flying from the tap- 
hole due to the use of wet bod material, cold or wet tapping 
bars, etc. 

It also makes it unnecessary for men to get in each other's 
way at the cupola, as is always the ca'^e when catchmg over 
with small bull ladles. The chance of the stream getting away 
from the men and falling upon the floor is greatly reduced, and 
for these reasons one of these devices should be used in every 
foundry as a protection to moulders and cupol.i men. 

Another plan for running a continuous stream is by use of 
the cupola reservoir or crucible shown in Figs. 6i and 71, 
This system of melting has never been [)opular in this country, 
but is advocated by the manufacturer of the Baillot cupola, who 
make great claims for it. The objection to this system of 
melting is that the iron becomes too dull for pouring light work. 



CHAPTER XX. 

NUMBER OF MEN REQUIRED TO MAN A CUPOLA. 

A QUESTION frequently asked by foundrymen is how many 
cupola men are required to melt a given amount of iron in one 
or more cupolas. This is a very difficult question to answer 
accurately owing to the variety of conditions met with at dif- 
ferent foundries, such as the amount of remelt iron to be col- 
lected from the foundry, whether it is milled or not, distance 
pig iron and fuel have to be transported from stock yard to 
cupola, condition of yard in wet and dry weather, means of 
transportation, whether by wheelbarrow, track and car, horse 
and cart, cranes, etc., means of raising stock to cupola scaffold, 
whether by throwing it up from one platform to another, wheel- 
ing it up a runway in barrows, or drawing it up a runway with a 
rope or chain on cars and track, or lifting by fast or slow ele- 
vator, cranes, etc. These conditions increase or decrease the 
amount of labor required. Another element to be considered 
is the kind of help employed. In the south, with colored help, 
more cupola men are generally required to melt a given amount 
of iron than in the north with white or mixed help. 

Mr. J. W. Keep, who has recently made an investigation as 
to the number of cupola men required in a number of stove 
foundries, makes the following report in the Foundry: 

( 1 ) One man does all of the work for a 2 i^^-ton melt, 3 tons 
being the limit. He repairs his cupola, taps out, wheels and 
weighs the iron, limestone and coke, wheels out the sprues and 
charges all of the material in the cupola. 

(2) Another stove foundry employing 166 moulders and 
melting 34 tons of iron requires only five men to operate its 
cupola. This includes the handling of all material, and one 

(323 ) 



324 THE CUPOLA FURNACE. 

man taps out the iron while four men weigh the material and 
charge the cupola. These men wheel out all the sprues, and 
as no cinder- mill is used, pick over the bottom. However, a 
sixth man is employed to daub ladles and tap slag when melt- 
ing. The material is handled in the yard in wheelbarrows, and 
is hoisted to the charging floor by an elevator. 

(3) Another stove foundry requires six men for a melt of 
2 2 tons of iron. The material is conveyed in wheelbarrows 
up an incline. The ladles are daubed by a separate man. 

(4) Another large stove foundry melting 8o tons of iron in 
three cupolas requires 15 men to handle the material. The 
iron is charged in cars handled by a crane, that reaches all 
parts of the foundry yard. Tlie limestone is conveyed to each 
charging platform by a crane. The charges are weighed and 
the sprews, coke, etc., are placed on the cars with the iron, and 
these charges are run to each cupola over tracks. Flat cars 
provided with boxes are used in the foundry for handling the 
sprues and scrap, and these after being conveyed to the yard 
are hoisted by the crane to the weighing platform or to a stor- 
age track. Fourteen cars of coke are loaded and placed on 
the storage tracks for each succeeding day's melt. This work 
requires two men in the yard, two men on the weighing plat- 
form, four men at each of two cupolas, and two men at the third. 
Including the crane operator, 15 men are required for the 80 
ton melt. The ladles are daubed by another employee; the 
man who taps the iron also keeps the slag running. One hun- 
dred tons could be melted by this crew, but the distribution of 
the work in the foundry would necesitate the installation of an- 
other cupola, and therefore, four additional men. Four men 
could easily do the work at each of the two larger cupolas in 
the winter time, but in as much as an additional man has to be 
added at each furnace in summer, it was decided to employ the 
entire crew throughout the year. 

The melt compared with the necessary charging-floor labor 
can be summed up as follows. 
( I ) One man 3 tons. 



NUMBER OF MEN REQUIRED TO MAN A CUPOLA. 325 

(2) One man 6f tons. 

(3) One man 3^ tons. 

(4) One man 5^ tons. 

The labor of the second foundry shows that the melting is 
most economical in the pecentage of labor employed. "I am 
not certain whether uniform iron can be obtained by dumping 
the entire charge of coke and iron into the cupola at once, al- 
though in all these cases the charging was done very care- 
fully.— (J. W. K.). 

The above heats were all melted in stove foundries, in which 
the sprues and remelt averages about 40^1^' of the heat melted, 
and more time and labor are required to collect this iron than 
in a machine or jobbing foundry where remelt frequently does 
not amount to 5/0 of the heat. In small foundries it is the 
practice to only have one cupola man and, in case of an extra 
heavy heat or large ladles to be daubed, to give him a helper 
for a few hours. But this plan is not practicable where a num- 
ber of cupola men is employed for if given extra help one day, 
they aim to get it every day and an extra man soon has to be 
regularly employed to get the work done. When a number of 
cupola men are employed the work should be divided up so 
that each man has his task to do. 

DEVICES FOR CHARGING CUPOLAS. • 

The charging or placing of fuel and iron in cupolas has 
always been done by handling the stock at the charging door. 
In the handling of stock for a large rapid melting cupola more 
men are frequently required to keep the cupola filled than can 
be worked to advantage at one or more charging doors, and 
stock gets too low in the cupola for rapid melting. To over- 
come this trouble and reduce expense for cupola labor a num- 
ber of devices have been arranged for automatic or rapid charg- 
ing. At the plant of the Carnegie Steel Works, Homestead, 
Pa., the stacks of their large cupolas are supported on iron 
columns, three feet long, leaving an opening all around the 
cupola for charging. This opening is only a few inches above 



326 THE CUPOLA FURNACE. 

the scaffold floor, and admits of charging being done direct 
from two-wheeled iron barrows of the blast furnace type, which 
dump from the front or end of the barrow. These barrows are 
wheeled from the elevator and coke or iron is dumped direct 
into the cupola. This method reduces the cupola labor to a 
considerable extent and has proven very satisfactory at this 
plant, where an iron of a very hot, even temperature is not re- 
quired. An endless chain carrying and charging device de- 
signed and put in use at a foundry in Indianapolis, Ind., was 
exhibited to the members of The American Foundrymens' As- 
sociation during their meeting at that city a few years ago. 
This device at that time was claimed to be a success, but an 
inquiry by the writer at this plant last spring elicited the infor- 
mation that it was riot then in use, and the superintendent of the 
foundry at that time in charge had never seen or heard of it» 
It therefore could not have been much of a success. An Eng- 
lish charging device recently described in the iron and foundry 
publications consists of a round iron car of the diameter of the 
cupola to be charged. This car is provided with a drop 
bottom and the charges of coke or iron properly mixed and 
arranged are placed in the car which is run over the cupola 
where the bottom is dropped and the charge dumped into the 
cupola. This device admits of even charging and promises 
more of a success than any other yet devised and put in use. 

Another device for direct charging that might be used to ad- 
vantage and no doubt will be tried in the near future, is the 
lifting magnet illustrated in Fig. 57. By means of this magnet, 
iron may be lifted direct from the yard or cars and dropped 
into the cupola, and only the fuel would have to be charged by 
hand. But like the English device above described, this can 
only be done when the cupola is of a sufificient height and so 
situated that the stack can be dispensed with. 

A number of other devices for this purpose that have been 
placed in use might be mentioned, but those described are 
among the best and probably sufificient to outline the work that 
has been done in this direction. 



NUMBER OF MEN REQUIRED TO xMAN A CUPOLA. 327 

The great trouble with all such devices is that they do not 
distribute the fuel evenly over the charges of iron, and do not 
pack or place the iron in a cupola to utilize all the heat of the 
fuel. Hence the cupula does not melt iron of an even tempera- 
ture throughout a heat, and this has rendered all such devices 
unsuitable for castings requiring a hot, fluid, even iron. 

SMALL CHARGES FOR A CUPOLA. 

In an article on cupola management, written by Doctor 
Moldenke, and published a year or more ago in the foundry 
periodicals, the doctor made the claim, that by making the 
charges of fuel and iron light, less fuel was required, the cupola 
melied f.istcr, and a more even iron was obtained at the spout. 
Since the publication of this article a number of foundrymen 
have tried this system of charging and published their re^^ults. 
Some claim better results, while others stated that this system 
was a complete failure in their cupolas. The writer has met 
many other foundrymen who have tried the system without 
publishing result-^, and they report similar results, that is, suc- 
cess in some cupolas and failures in others. This proves the 
theory that I have always advocated, that every cupola is a law 
unto itself, and that scarcely any two cupolas can be charged 
exactly alike, and the best results that may be obtained pro- 
duced. A little investigation of cupola charging will show that 
there is a very wide difference in the weight of charges of fuel 
and iron placed in cupolas of the same diameter in different 
foundries, and frequently in the same foundry. This difference 
in weight of charges is sometimes two or three times that of 
the weight of others for cupolas of the same diameter. Never- 
theless, these varying charges give a good hot even iron from 
the cupola in which they are melted, which would probably not 
be the case were the charges reversed and the heavy ones put 
in cupolas melting light charges. It is therefore apparent, that 
to obtain the best results from a cupola, the weights of charges 
of fuel and iron should be varied until these results are ob- 
tained. Dr. Moldenke's theory is no doubt correct for many 



328 THE CUPOLA FURNACE, 

cupolas, and especially for small ones, in which the fuel may be 
concentrated and in many of which the best results are obtained 
from small charges. But I should not recommend it for large 
cupolas in which a very thin layer of fuel between the charges 
of iron, if not very evenly distributed, is liable to permit the 
iron to sink below the melting zone before melting, and produce 
foaming slag, dull iron, or not be melted at all. 

RETAINING HEAT IN A FOUNDRY. 

Cupolas, years ago, were generally placed outside the foun- 
dry or in a cupola room with a spout extending into the foun- 
dry, but of late years they are commonly placed at the most 
convenient point from which to distribute molten iron to work 
to be cast, this being near the center of the foundry on the 
gangway or on the side. In this position, a cupola when not 
made up for a heat acts as a perfect funnel for drawing heat 
from the foundry during the winter months, and the coldest 
moulding floors are those nearest the cupola. 

This waste of heat may be readily prevented by placing one 
or two doors on top of the cupola stack, to serve as a damper 
when the cupola is not in blast or made up for a heat. These 
doors are not subjected to any great heat and' may be made 
of boiler plate and hinged to the top of the stack, with an 
arm or other device attached to each door, for raising or 
lowering it by means of a chain or rod from the foundry floor 
or scafifold. 

For cupolas of small diameter one door is sufificient, but for 
large cupolas double doors are the best, as they are more easy 
to raise and lower, and do not stand up so high when raised. 
These doors, when stood straight up, do not interfere with the 
draft of the cupola when lighting up, and are out of the way 
when the cupola is in blast. If closed as soon as the bottom is 
dropped, and the dump wetted a little, they retain all the heat 
of the dump, hot castings and warm sand in the foundry, and 
the foundry will be found many degrees warmer in the morning. 

Another way of arranging the cupola damper to prevent the 



NUMBER OF MEN REQUIRED TO MAN A CUPOLA. 329 

escape of heat from the foundry, and at the same time to have 
a spark arrester over the cupola, is to hang a spark arrester 
over the cupola upon a lever in such a way that it may be let 
down upon the top of the stack by means of a chain or rod 
from the foundry floor or scaffold. Either of these devices 
may be arranged at very little cost and effect a considerable 
saving in fuel for heating a foundry during the winter months. 

PROTECTING THE MELTER WHEN CHIPPING OUT. 

At this time when the American Foundrymen's Association 
have a committee investigating accidents in foundries with a 
view of preventing men being injured in the performance of 
their daily work, it might be well to call attention to a constant 
danger to the melter when chipping out the cupola in making 
it up for a heat. In this work, heavy sledges and picks have 
frequently to be used to remove bridging and hard lumps that 
adhere to the lining, and in so doing the lining is jarred from 
the bottom of the cupola to the top of the stack. This jarring 
frequently causes bricks to fall from the top of the stack where 
they have been loosened by the heat and by the weather freez- 
ing or washing out the grouting or mortar between them ; or 
slag adhering to the stack lining, and deposits of oxides upon 
the spark arresters to drop down upon the melter, and man}' 
melters have been injured and some killed in this way. This 
danger is principally from the stack, and a very efficient and 
inexpensive way of lessening it is as follows: Take a board or 
light plank eight or ten feet long and the width of the charging 
door. Round ofif one end of it to the diameter of the cupola, 
and to the other end fix a hinged leg for a support. Attach to 
each side of the board with strap hinges a circular piece so 
that these pieces, when let down, completely fill the cupola; a 
cross-piece to support these wings may be nailed to the under- 
side. Push the board, rounded-ofF end foremost, into the 
cupola through the charging door, let down the wings, adjust 
the hinged leg under the other end of the board and place 
upon it a few pieces of pig iron to prevent it from being tipped 



330 THE CUPOLA FURNACE. 

by anything that may fall upon it. This device when con- 
structed of light lumber is very easily adjusted and removed, 
and when not in use may be set on end in a corner out of the 
way. A device may also be constructed of boiler plate or 
boards, consisting of a centerpiece and two hinged side pieces 
to form a circle, which is braced against the Iming when in 
place, but such a device is more difficult to get into and hold 
in place than the above device. 

PIG BED. 

Pig beds for little drops of iron left over in ladles, and pig- 
ging out after a heat, are placed near a cupola, where they are 
always more or less in the way and frequently tramped over 
in casting, and the pig moulds destroyed. Tliis trouble may 
be overcome by placing iron pig moulds. Fig. 62, in the gang- 
way for iron from ladles, and 
Fig. 62. . • • 1 1 ^ 

constructing a pit-pig bed for 

pigging out. This is done by 
casting four plates and placing 
them in the floor to form a frame, 
the top of which comes just 
about level with the foundry 
floor. Inside of this frame the pig moulds are made in sand, 
to come just below the top of the frame, and covered with 
plates which rest upon the frame, over which a little sand may 
be thrown to prevent molten iron spattering in case any is 
spilled upon them from ladles. After the heat is over, the 
plates are removed with a couple of hooks provided for the 
purpose, and the pig moulds are ready for any over iron that 
may be in the cupola. This arrangement places the pig bed 
entirely out of the way and gives more floor space about the 
cupola for the handling of iron in the ladles. Another good 
way of protecting the pig bed is to provide a sufficient number 
of patterns for the entire bed and permit these patterns to re- 
main in the moulds until ready to pig out, when they are 
removed. This arrangement admits of the pig bed being 




NUMBER OF MEN REQUIRED TO MAN A CUPOLA. 33 1 

tramped over in handling iron in ladles without destroying the 
pig moulds. Either of these arrangements may be found pre- 
ferable to forming pig moulds with a shovel and casting rough 
slabs of iron that have to be broken up while hot and are diffi- 
cult to handle and remclt. 

BOILING OR FOAMING SLAG. 

So large a quantity of slag occasionally forms in a cupola 
that it boils and foams until it fills the cupola to the charging 
door, and may run out at the latter. This phenomenon gener- 
ally occurs at the end of the heat, and is due to too small a 
quantity of fuel being used between the charges of iron, and 
the latter sinking too low in the melting zone before melting. 
At this point, when in a semi molten state, it is struck by a 
strong blast from the tuyeres, which has a bessemerizing effect 
uDon it, and a large per cent, of it is converted into slag, which 
is made to boil and foam in the cupola by a strong blast pass- 
ing directly into it from the tuyere. This slag contains a large 
per cent, of iron, and the loss of the latter in melting is very 
heavy. 

Boiling slag may also be due to uneven distribution of fuel, 
or an excess of it being thrown upon one side of the cupola. 
In this case the slag is only formed on one side of the cupola 
or in front of one or more tuyeres, and if the trouble is soon 
remedied by an excess of fuel settling down at this point, the 
only effect will be to produce an excess of slag at the iron or 
slag tap hole. But if this does not occur, the cupola only melts 
on one side and the iron is made dull and harder by oxidized 
iron mixing with it, and when stock gets low in the cupola, the 
slag boils and foams up to the charging door, and melting al- 
most entirely stops. When a cupola gets into this condition, 
the only thing to do is to drop the bottom, and this should be 
done before the blast is taken ofT, to prevent the tuyeres and 
air chamber from being filled with slag. 



332 THE CUPOLA FURNACE. 

TREATMENT OF BURNS. 

In many of the large foundries scarcely a day passes but 
men are burned in handling hot iron in ladles. Linseed oil 
and lime water are generally kept at hand for the treatment of 
such burns. But this remedy is slow in action and difficult to 
keep in place, and small burns are frequently neglected, result- 
ing in bad sores. 

A much better remedy is a fine grade of new moulding sand 
moistened with glycerine to the consistency of a thin putty. 
This remedy, if at once applied, draws out the fire very quickly 
and admits of the burn healing rapidly. A small piece of 
gauze or thin white cloth placed over the burn before applying 
the remedy keeps the burn clean and does not interfere with 
the action of the remedy. For drawing the fire put the remedy 
on thick, and for healing spread it on very thin. 

Another good remedy is antiphlogistine, a preparation of 
white clay sold in drug stores. This preparation acts very 
similarly to the moulding sand remedy and is applied in the 
same way. It is however much cleaner, and may be applied 
direct to the burn for healing, and washed ofT when dressing 
the burn. Should this or the sand remedy draw the sore too 
much for rapid healing, apply a thinner layer. Sores from 
burns are retarded from healing by exposure to the air, and 
should only be dressed once a day, and if kept clean, once in 
two or three days is sufficient. 

If no other remedy is at hand a little clay from the cupola 
daubing trough is a good one for drawing the fire from a burn 
and giving prompt relief. Apply it thick and tie it up to ex- 
clude the air. 

NEW METHOD OF MIXING DAUBING. 

In some of the larger foundries using a great deal of daubing 
material, it has been found to be more economical to dry and 
grind the clay before mixing it with the sand, than to soak the 
the clay and mix the sand after soaking. A common stave 
tumbling barrel is provided for this purpose. The clay is 



n 



NUMBER OF MEN REQUIRED TO MAN A CUPOLA. 333 

thrown into the barrel with a proper amount of pig iron to 
break it up and reduce it to a powder. When this has been 
done, the clay is again thrown into the mill with the proper 
amount of sharp or fire sand, and the two thoroughly mixed. 
The mixture is then placed in a mixing trough and wetted up 
and, while the mill man is waiting for a mill full to be ground, 
he hoes it over and makes it ready for application to the cupola. 
This method gives an even mixed daubing that does not crack 
when heated or fall ofT in spots from containing an excess of 
clay or sand. It is also claimed to save considerable time and 
expense, for it is said, that in no part of cupola manipulation can 
cupola men put in more time than in hoeing over a trough of 
daubing. 

This method also has the advantage of reducing the mixing 
of daubing to a science, for it enables the founder to accurately 
determine the per cent of clay and sand, that gives the best re- 
sult in melting from the grade of clay and sand used, and to 
determine if a difTerent grade of either would give better results. 

This is a matter which cannot be accurately determined with 
any degree of certainty when cupola men are depended upon 
to do the mixing, because in many cases the greatest quantity 
of material that is easiest to shovel and mix, is used regardless 
of results obtained in melting, 

This system of mixing is applicable to small as well as large 
plants, as an ordinary tumbling barrel may be used for the 
grinding and mixing, and when mixed, the material may be 
binned or barreled. It is then only necessary to wet and hoe 
it over to ensure an even temper of the daubing. 

Grinding and mixing may also be done in any of the sand 
mixers used in foundries, but in this case the cla}' must be per- 
fectly dry and broken small to prevent clogging in the mixer. 

Another way of mixing daubing is by the wet process in the 
roller mill. With this mill no drying of the clay is necessary, 
and when mixed, the daubing is ready for application to the 
cupola. However, only foundries using rope cores, coated 
with loam, or doing a large amount of loam work, have this 



334 '^"HE CUPOLA FURNACE. 

mill in use, and it is too expensive to install for this purpose 
only in any but large plants. 

RENEWING A LINING. 

In many of the large cupolas, melting from fifty to one hun- 
dred tons of iron at a heat, the destruction of lining material is 
very great. Four inches of lining are frequently burned out at 
the melting zone in one or two heats, and this thickness of lin- 
ing seldom lasts more than a week before it has to be renewed 
with new brick. A good plan of renewing this lining, is to 
place in the cupola at this point a lighter permanent lining 
than desired, and inside of this lining place a lining of four-inch 
brick to reduce the cupola to the desired diameter. Such a 
lining is equally as refractory as the permanent lining and may 
be removed and rejjlaced with new brick in a very short time 
without disturbing the permanent lining. This method of re- 
newing a lining has proven very satisfactory in a number of 
plants melting large heats, and may also be adopted by those 
melting small heats in which the destruction of lining is heavy. 

MICA SCHIST LINING. 

Mica schist * or fire stone, as it is sometimes called, is a soft 
rock that has been used for some time in lining steel convert- 
ers and furnaces, and is now coming into use for cupola linings. 
This material may be readily broken, and crumbles easily when 
handled, and cannot be cut into shape for lining before ship- 
ment. It is therefore used in its natural state as it comes from 
the mines and fitted to the cupola as the lining is laid up. 
The small pieces or crumbs that are broken off in handling and 
fitting the lining are mashed up and mixed with a little fire 
clay ; this makes a fire mortar that stands the heat equally as 
well as the solid rock, and when heated cements the entire lining 

* Mica schist, although an excellent lining material, does not appear to have come 
into use to any gn-at extent as a cupola lining sin^e the publication of the second 
edition of this work. The great objection to it appears to be the time required for 
putting in a lining. 



NUMBER OF MBN REQUHIED TO MAN A CUPOLA. 335 

into a solid mass that glazes and does not spall off and fall out 
so easily as fire brick. 

At several foundries where this lining was being used we 
were informed that it was giving excellent results, and required 
less daubing and repair than fire brick. At one large foundry 
where a lining of this material had only recently been put in, 
we were told that the lining material for their cupola had cost 
less than one-fourth the cost of fire brick for the same cupola ; 
and while the cost of putting it in was a little greater, the lining 
when in had cost less than one-half that of fire brick, and in 
the few heats they had melted with it, it had not been cut out 
to so great an extent as with brick. 

When putting in a lining of this material all backing or fill- 
ing put in with fire brick should be removed and the lining 
made as thick as possible, for the thicker it is the more readily 
and quickly it may be laid up, and a backing is not required 
with it. 

There are several other native lining materials in the market, 
such as ganister and mica soap-stone, that may be used to 
advantage when cost of transportation is not too great. 

COMMON RKD BRICK LINING. 

The question of lining with common red brick bobs up every 
once in a Vv'hile as something new, cheap and economical. 

We have seen many cupolas lined with this material in days 
when fire brick was not so cheap or easily obtainable as at 
the present time. The softer bricks were generally selected, 
and they were set on end with the edges to the fire, and two 
thicknesses of them were generally put in. 

These linings answered the purpose very well for the small 
heats commonly melted in those days, but with the heats 
melted in many cupolas at the present time it is doubtful if 
they would last through one heat; and even when heats are 
light, they are a more costly lining in the long run than the 
more expensive fire brick or other material, for they require to 
be replaced very frequently at the melting zone, which neces- 



336 THE CUPOLA FURNACE. 

sitates taking a day or having the melter and helper work on 
Sunday, and this in time costs more than good lining material. 
Use only the best of lining material and the best of daubing 
material for keeping it up, and you will reduce cost of melting 
more than by using cheap material. 

moor's patent cupola breast and runner. 

The breast and spout are made of the same material as a 
plumbago crucible for melting steel or brass, or of fire clay, and 
baked in an oven the same as crucibles and fire brick. This 
breast and spout are designed to replace the common loam and 
clay breast and spout made up every heat and save material 
and labor in making them up. The runner is made to order 
to fit the cupola spout, the iron running over it to the ladle. 
It will last for three or four years with care. Runners are also 
made for slag spouts or in fact any spout where iron, steel or 
brass is run. It saves the clay or loam to make and mend it, 
and the time in doing so. The breast will not only do away 
with the old clay or loam breast, but relieves the foreman of 
much responsibility. It should last six to eight months. The 
breasts are kept in stock and may be readily fitted to any 
cupola. With this breast and spout always in place, it is only 
necessary to make the sand bottom up to suit the tap hole and 
much material and labor are saved. The size of tap hole may 
be regulated by use of thimble or ring, or by placing a bod 
in the hole and making an opening through it of any desired 
size with a tap bar. These are the claims made for this breast 
and spout. 



CHAPTER XXI. 

SCIENTIFICALLY DESIGNED CUPOLAS. 

That the cupola designer has not been idle will readily be 
seen by the following illustrations and descriptions of a few of 
the many designs of cupolas that have been constructed and 
placed in the foundries of this and foreign countries. Each of 
these cupolas embraces some practical or scientific point not 
found in the others, and designed to better suit it for the work 
to be cast, fast melting, slow, continuous melting, holding mol- 
ten iron, economy in fuel, blast, lining material, labor, etc. 
Each of these cupolas presents some fine points in melting or 
other purpose for which it was designed, and was no doubt a 
great improvement over the one it replaced, but it is much 
easier to design and construct a cupola upon scientific lines 
with fine points than it is to maintain it. Thus a flat cupola 
admits of blast being more evenly distributed to the stock than 
a round one, but the increased tendency of the cupola to bridge 
and bung up, and lining to collapse, makes this design imprac- 
ticable. Some of the various shaped linings present scientific 
points in the distribution of blast and settling of the stock, but 
the difficulty of maintaining the lining in this shape renders 
these points useless. The arrangement of tuyeres and distri- 
bution of blast upon scientific principles has produced perfect 
combustion of fuel, rapid and economic melting, but changes 
in shape of lining, difficulty of keeping small tuyeres open, etc., 
have destroyed this effect. Another objection to these scien- 
tific, fancy-designed cupolas is the class of men employed in 
manipulating cupolas. As a rule these men are not scientists, 
and cannot see the advantages of maintaining the finer points, 
and while one melter may manage one of these cupolas suc- 
cessfully for years, the next one may make a complete failure 
22 (337) 



338 THE CUPOLA FURNACE. 

of it. For these reasons the fancy-shaped or designed cupola 
has as a rule been forced to give place to the straight-line, 
cylindrical one with abundant tuyere area and high charging 
door, which is more easily manipulated than any other with the 
help obtainable, and while it may not give the best results indi- 
cated by science, it gives the best practical results for the 
founder, 

OLD SlYLE STAVE CUPOLA, 

In Fig. 63 is seen the old style cupola in general use through- 
out the country many years ago, some of which are still in use 
in old-time small foundries. A square cast-iron bottom plate, 
with opening in the center and drop door, is placed upon a 
brick foundation at a sufificient height above the floor for the 
removal of the dump. An iron column is placed upon each 
corner of the plate, and upon these columns is placed another 
cast-iron plate, having an opening in the centre for the top of 
the cupola. Upon this plate a brick stack is constructed to 
carry ofT the flame and unconsumcd gases. The stack plate 
was sometimes placed upon brick columns or brick walls, 
built on each side of the cupola, through which openings 
were made for manipulating the tuyere elbows. The stack 
was built square and of a much larger size than the inside 
diameter of the cupola. It was not subjected to a very high 
heat, and was built of common red brick. These large stacks 
were not built very high and threw out very few sparks at 
the top, which was due to their size. The cupola was placed 
between the bottom and stack plate, and the casing was formed 
of cast-iron staves, which were held together by wrought-iron 
bands, drawn tight by draw-bolts placed through the flanged 
ends of the bands. When the casing was made tapering, the 
bands were placed in position when hot and shrunk on. The 
cupolas were only from six to eight feet high, and those of 
small diameter, were generally made larger at the bottom than 
at the top, to facilitate dropping, and that a large quantity of 
molten iron might be held in the cupola for a heavy casting. 



SCIENTIFICALLY DESIGNED CUPOLAS. 



339 



The charging door was placed in the stack just above the stack 
plate. From two to four tuyeres were put upon each side of 



Fig. 63. 




OLD STYLE CUPOLA. 



340 THE CUPOLA FURNACE. 

the cupola, one above the other, and from eight to ten inches 
apart. The tuyeres were supplied from a blast-pipe on each 
side, to which was attached a flexible leather hose and a tin or 
copper elbow for conducting the blast into the tuyeres. A 
small hole was made at the bend of the elbow for looking into 
the tuyere, and closed with a wooden plug. The tuyeres were 
frequently poked with an iron bar through these openings. 

When light work was to be cast, the upper tuyeres were 
closed with clay or loam, and the blast sent through the lower 
tuyere. When it was desired to accumulate a large amount of 
molten iron in the cupola for a heavy piece of work, the lower 
tuyeres were used until the molten iron rose to the lower edge. 
The tuyere elbows were then withdrawn and shifted to the next 
tuyere above, and the lower tuyere closed with clay or loam 
rammed in solid. The shifting of the tuyere elbows was con- 
tinued in this way until the necessary amount of molten iron 
for the work to be cast was accumulated in the cupola. When 
a heavy piece of work was to be cast, a sufificient quantity of 
fuel was placed in the cupola to bring the top of the bed some 
distance above the top of the highest tuyere to be used ; on 
the bed two cwt. of iron was charged, and a shovelful of coke 
and a cwt. of iron charged throughout the heat. The charging 
was raised a little in different sized cupolas, but the fuel and 
iron were always mixing in charging. The large body of 
molten metal frequently pressed out the front and sometimes 
the plugging of the lower tuyeres. After the iron was tapped 
the stock in the cupola dropped so low that no further melting 
could be done with the blast in the upper tuyeres, and fre- 
quently the lower tuyeres were so clogged that they could not 
be opened, and the bottom had to be dropped. 

In practice it was found that in a cupola constructed large at 
the bottom and small at the top for the purpose of retaining a 
large amount of molten iron, the stock did not spread to fill the 
cupola as it settled, and a great deal of heat escaped through 
the space made between the lining and stock by the settling of 
the latter. It was also found that the shifting of tuyeres re- 






SCIENTIFICALLY DESIGNED CUPOLAS. 



341 



•quired Jsuch a high bed that the cupola melted slowly, and a 
greater per cent, of fuel was consumed in large than in small 
heats. 

Fic.. 64. 




RESERVOIR CUPOLA. 



342 THE CUPOLA FURNACE. 

THE RESERVOIR CUPOLA. 

To overcome the objection to the tapering cupola and shift- 
ing of the tuyeres, and still be able to hold a large amount of 
molten iron in a cupola, the reservoir cupola, Fig. 64, was 
designed. 

The casing of this cupola was made of wrought iron, and the 
bottom section, to a height of from twelve to twenty-four inches, 
was constructed of one-third greater diameter than the upper 
section or cupola proper. This arrangement admitted of a 
large body of molten iron being held in the cupola without 
shifting the tuyeres. The metal was spread over a larger sur- 
face, which reduced the pressure on the breast, and did not 
leave the stock in so bad a condition for melting after a large 
tap was made as in the tapered cupola, and melting could be 
continued after a large body of iron was tapped. The reservoir 
cupola did faster and more economical melting in large heats 
than the tapered cupola, but in small heats the amount of fuel 
required for the bed was too large for economical melting. 

At the present time cupolas are made of the same diameter 
from the bottom to six or eight inches above the tuyeres. The 
tuyeres are placed at a height to suit the general run of work 
to be done, and when a heavy piece is to be cast, the iron is 
held in ladles and covered with charcoal or small coke to ex- 
clude the air. The molten iron can in this way be kept hotter 
for pouring than in the cupola, and the cupola is kept in better 
condition and melts faster and longer. 

EXPANDING CUPOLA. 

Fig. 65 is a sectional elevation of the expanding cupola, 
which is said to have melted very rapidly and with very 
little fuel. This peculiar form was designed to admit of the 
charging of a large quantity of iron before putting on the blast, 
for the purpose of utilizing all the heat produced by the com- 
bustion of the fuel. These cupolas were built of common brick, 
banded with wrought- iron band and lined with firebrick. The 
diameter at the charging door was sixty inches and at the 



SCIENTIFICALLY DESIGNED CUPOLAS. 
Fig. 65. 



343 




EXPANDING CUPOLA. 



344 THE CUPOLA FURNACE. 

tuyeres thirty inches, or one-half the diameter at the charging 
door. Below the tuyeres the lining expanded to forty or even 
fifty inches, to give room for molten metal. The bottom was 
stationary, and the refuse after meltmg was drawn at the front. 
The cupola expanded from a level a little above the tuyeres to 
the bottom of the charging door, thence to the top of the stack 
it gradually contracted. 

The greatly increased diameter at the charging door certainly 
admitted of a large quantity of iron being placed in the cupola 
at one time, and the utilization of a very large per cent, of the 
heat in melting. The even taper of the lining insured the even 
settling of the stock, so that good melting should have been 
done in this cupola ; but the best results obtained appear to have 
been about six and a half pounds of iron to the pound of coke. 

This old form might be used to advantage in the construc- 
tion of very large cupolas ; but in the ordinary sized cupola, 
practically the same results are obtained by boshing or con- 
tracting the lining at the tuyeres, and making it straight from 
the top of the boshes to the charging door. 

Ireland's cupola. 

Ireland's cupola, for which the inventor took out a number 
of patents in England about 1856, and which was largely used 
there about that time, and is still the leading cupola in England, 
was constructed of a variety of shapes and sizes, but probably 
the best design is that shown in sectional view Fig. 66. It is 
built with a bosh and contraction of the diameter at the tuyeres, 
and has a cavity of enlarged diameter below them to give in- 
creased capacity for retaining molten metal in the cupola. 

The cupola, of which a section is shown, was twenty-five feet 
high from bottom plate to top of stack, twelve feet from bottom 
plate to sill of charging door. The shell was parallel and fifty 
inches diameter to the charging door, thence it gradually 
tapered to two feet three inches at the top. There were two 
rows of tuyeres eighteen inches apart, eight in the upper row, 
two inches diameter, and four in the lower row, six inches 



SCIENTIFICALLY DESIGNED CUPOLAS. 



345 



•diameter. The cupola was constructed with stationary bottom 
-and draw front. 

Fig. 66. 




Ireland's double tuyere cupola. 



346 THE CUPOLA FURNACE. 

It was at first proposed to use a hot blast in the top row of 
tuyeres, but it was found to be difficult and expensive to heat 
the blast, and that nothing was gained by using the upper row 
with a cold blast, and they were closed and the cupola con- 
structed with only the lower row of tuyeres. The interior shape 
was slightly modified to give more space for retaining molten 
metal, while, at the same time, retaining the boshes and in- 
creasing the diameter of the bottom of the cupola, as seen in 
the Fig. 66. Two of these cupolas were used by the Bolton 
Steel and Iron Company in England, in melting the iron for a 
large anvil block weighing two hundred and five tons, for which 
two hundred and twenty tons of metal, including eight tons 
Bessemer steel, were used. 

The cupolas were each seven feet outside diameter, three feet 
nine inches diameter below the boshes in the crucible, and five 
feet diameter above and below the crucible. The blast was sup- 
plied from an external air-chamber, extending round the casing 
and delivered into the cupolas through two rows of tuyeres 
placed eighteen inches apart, sixteen in the upper row of three 
inches diameter, and four in the lower row of eight inches diam- 
eter. The metal was melted in ten hours and forty-five minutes 
from the time of putting on the blast until the mold was filled, 
and only one hundjed and twenty-five pounds of coke con- 
sumed per ton of metal. Slag was tapped from the slag hole 
A below the tuyeres throughout the heat. 

Ireland's center blast cupola. 

In Fig. 6y is seen a sectional elevation of Ireland's cupola 
with bottom tuyere. The height from bottom plate to top of 
stack is twenty-seven feet, from bottom plate to sill of charging 
door twelve feet. The casing is parallel from the bottom plate 
to charging door, and thence it gradually tapers to the top ; 
diameter of casing up to charging door four feet six inches, 
tapering to two feet six inches at the top of stack. The inside 
diameter at bottom of crucible, on the cupola hearth L, is two 
feet six inches, contracting to two feet three inches at spring of 



SCIENTIFICALLY DESIGNED CUPOLAS. 
Fig. 67. 



347 




IRELAND'S CENTER BLAST CUPOLA. 



348 THE CUPOLA FURNACE. 

the bosh A A, and three feet nine inches diameter from top of 
bosh to charging door, whence it tapers to one foot nine inches 
at top of stack. Height of crucible four feet five inches, length 
of boshes from AA to BB, eighteen inches; height from top of 
bosh to charging door, six feet seven inches. The blast is sup- 
plied from one tuyere placed in the center of the bottom of 
crucible. 

The tuyere hole through the iron bottom is nine inches 
diameter, into which is passed a seven and a half-inch water 
tuyere, the mouth of which, //, is two feet above the sand 
bottom L. A slag hole A'^, five inches diameter, is placed just 
below the level of the mouth of the tuyere. P is the tap-hole 
and spout. 

This cupola melted three tons of iron per hour with two and 
a-half cwt. of coke per ton, but it does not appear to have given 
satisfaction, for it never came into general use in England or 
this country, and Mr. Ireland changed his plans and constructed 
his cupolas with side tuyeres. 

voisin's cupola. 

In illustration Fig. 68 is seen a sectional elevation of Voisin's 
cupola, in which very good melting has been done. The shell 
is constructed of boiler plate with an external air chamber of 
the same material, extending all the way round the body of the 
cupola. This air chamber is supplied from two pipes, one on 
each side of the cupola. Two sets of tuyeres lead from the air 
belt into the cupola. Those of lower ,set are oblong, four in 
number, placed at equal distances apart and at right angles 
to the air belt. Those of the upper set are round, of less ca- 
pacity than those of the lower set, are placed horizontally 
through the lining and diagonally to the lower set, so that they 
are between them at a higher level. 

Mr. Voisin claims through this arrangement of the tuyeres, 
that the escaping gases are burnt in. the cupola, creating a 
second zone of fusion with those gases alone, and the second 
set of tuyeres obviates to some extent the evil effect of the 
formation of carbonic oxide in the cupola. 



SCIENTIFICALLY DESIGNED CUPOLAS. 
Fig. 68. 



349 




voisin's cupola. 



3 so THE CUPOLA FURNACE. 

This cupola is constructed in slightly varying shapes inside 
the lining, but the following dimensions give a general outline 
of it: Vertical dimensions from bottom to offset below tuy- 
eres, one foot ten inches ; offset below tuyeres to lower end 
of bosh, two feet four inches; length of bosh, one foot two 
inches ; top of bosh to charging door, six feet ten inches ; 
bottom of charging door to bottom of stack, two feet seven 
inches; taper to stack, three feet ten inches Horizontal 
dimensions: Below tuyeres, two feet; at tuyeres, one foot eight 
inches; at top of bosh, two feet four inches; at bottom of 
charging door, one foot ten inches ; at charging door, two feet 
seven inches. 

The casing is made straight from the bottom plate to taper 
to the stack, and to get the above dimensions it has to be lined 
with brick made especially for this cupola. 

Mr. Voisin has invented a number of different cupolas, but 
this one is said to give the best results in melting. 

woodward's steam jet cupola. 

In Fig. 69 is seen a sectional view, showing the construction 
of the Woodward steam-jet cupola in use to some extent in 
England. This cupola is worked by means of an induced cur- 
rent or strong draught caused by a steam-jet blown up the 
cupola stack, which is very much contracted just above the 
charging door. There are several different modes of applying 
the steam-jet, but the general principle will be at once under- 
stood from the illustration. The cupola is constructed upon 
the general plan of the English cupola, with a stationary bot- 
tom and draw front. Two rows of tuyeres or air-inlets, as they 
are termed, are placed radially at two different levels. In the 
lower row there are four openings, varying in size from five 
to eight inches in diameter, according to the size of the cupola. 
In the upper row there are eight, varying in diameter from 
three to five inches. Each of the air- inlets is provided with a 
cover outside, which can be closed when it is desired to shut off 
the draught. The upper row of air-inlets is placed from ten to 



SCIENTIFICALLY DESIGNED CUPOLAS. 
Fig. 6q. 



351 




WOODWARD STEAM-JET CUPOLA. 



352 THE CUPOLA FURNACE. 

fifteen inches above the lower row. The lining is contracted at 
the air-inlets to throw the air to the center of the stock, and en- 
larged below the air-inlets to admit of the retention of a large 
amount of molten iron in the cupola. 

The charges of fuel and iron are put in at the charging door 
A in alternate layers in the ordinary way, and the door is tightly 
closed and luted to prevent the admission of any air. The 
steam is then turned on through the nozzle B connected with 
the boiler by steam-pipe D, and the air-inlets N opened for the 
admission of air. When the cupola is working, the draught 
has to be regulated by the melter and care taken to close any 
air-inlets near which iron is seen to accumulate in a semi-fluid 
state. The temperature at the spot where the iron chills will 
soon rise to a degree that will cause the iron to run freely, when 
the air-ii^let may be again opened. All the iron to be melted 
is put in and the door closed before the steam is turned on. 
The charging may be continued throughout the heat, but the 
opening of the door has the same efTect on the stock as shutting 
off the blast in the ordinary cupola, and the melting stops. 
The repeated opening of the door soon gets the cupola into 
bad working order and it bungs up in a short time. 

When it is desired to use the cupola for continuous melting 
or for a larger amount of iron than can be put in at one time, it 
is constructed with a side flue and feeding hopper, as shown in 
Fig. 70. The general construction and air inlets are the same 
as those shown in Fig. 69. The stack is removed and the feed- 
ing hopper A with a sliding door B at the bottom, to be worked 
by the lever D, is placed on top of the cupola. The flue // 
near the top of the cupola connects it with the stack M, and the 
draught is induced by a steam- jet from the nozzle TV attached 
to the steam-pipe P. When filling the cupola, the bottom of 
the hopper is left open and the charges put in in the ordinary 
way until the cupola is filled. The bottom door of the hopper 
is then closed, and when the cupola is melting the charges of 
fuel and iron are put into the hopper and dropped into the 
cupola as the stock settles, and the door is at once closed to 
exclude the air at the top of the cupola. 



I 



SCIENTIFICALLY DESIGNED CUPOLAS. 
Fig. 70. 



353 




woodward's steam-jet cupola. 



23 



354 THE CUPOLA FURNACE. 

It is asserted by those interested in this cupola that it effects 
a great saving in fuel over the ordinary blast cupola. The con- 
sumption of coke in melting a ton of iron is placed at one hun- 
dred and fifty pounds, a very low rate of fuel ; but the same 
results are also claimed to have been obtained in blast cupolas 
of good design when properly worked. 

The steam required to create the draught is only equal in 
quantity to what would be required by an engine for driving a 
fan or blower of sufficient power to work an ordinary cupola of 
the same size. Considerable saving is effected in the first cost 
of engine and fan or blower, besides the saving in wear and 
tear of machinery. 

The objection to this style of cupola is the slow melting, for 
it cannot be forced beyond a certain point, and when a large 
amount of iron is to be melted the cupola must be kept work- 
ing all day. This does not meet the views of the foundrymen 
of this country, who desire to melt their heats in from one to 
two hours from the time the blast is put on until the bottom is 
dropped, and with that object in view construct their cupolas. 

TANK OR RESERVOIR CUPOLA. 

In Fig. 71 is seen a sectional elevation of a reservoir cupola. 
This cupola was designed for the purpose of making soft iron 
for light castings. It only differs in construction from the 
ordinary type in the reservoir or tank placed in front, which 
may be attached to any cupola. 

The cupola is set high, and the tank A is placed in front of 
it, with the cupola spout leading into it near the top. The 
molten iron is run from the cupola into the tank as fast as 
melted, and drawn from the tank-spout into the ladles as it may 
be required for pouring. The tank is made of boiler plate and 
lined with fire-clay or other refractory material, and is covered 
with an iron lid, lined likewise with same material. The spout 
and breast are made up the same as for an ordinary cupola. 
Before putting on the blast, the tank is filled with charcoal and 
closed with the cover; and as the iron melts, it is run into the 



SCIENTIFICALLY DESIGNED CUPOLAS. 
Fig. 71. 



355 




TANK OR RESERVOIR CUPOLA. 



356 THE CUPOLA FURNACE. 

tank, where it is allowed to remain a sufficient length of time 
to be carbonized and softened by the charcoal. 

These cupolas have been constructed in a number of differ- 
ent ways; the tank has been made of sufficient size to hold the 
entire heat of molten iron before pouring, so that the iron 
might be of an even grade throughout the heat and softened to 
a greater extent; and they have been riveted to the cupola 
casing and the lining continued from the cupola to the tank. 
In this latter case, the top is bolted or clamped to the tank and 
a tight joint made to prevent the escape of the blast, which has 
the same pressure in the tank as in the cupola. 

The tank cupola produces a softer iron than the ordinary 
cupola, but there is considerable additional expense attached 
to it in keeping up the tank and supplying it with charcoal. 
Another objection is the change made in the shrinkage of the 
iron ; that taken from the tank shrinks less than the same grade 
of iron when taken from the cupola, and when some parts of a 
machine or stove are made from the tank and other parts from 
the cupola, allowance must be made in the patterns for the 
difference in shrinkage. 

It is claimed by some founders that soft iron can be pro- 
duced by putting a quantity of charcoal on the sand bottom, 
and placing the shavings and wood for lighting the bed on top 
of the charcoal. In lighting up, the charcoal is not burned,, 
but remains in the cupola during the heat and may be found 
m the dump. This is the case if the tuyeres are high and the 
front is closed before lighting up; but if the tuyeres are low or 
the front and tap-hole are not closed, the charcoal will be 
burned out in lighting up the bed, the same as the wood. 

Tanks are, in England, used in connection with cupolas to 
som.e extent at the present time for mixing irons or to enable 
the founder to run a large casting or heat from a small cupola. 
The iron for an entire heat, requiring several hours to melt in a 
small cupola, is melted and run into the tank and drawn from 
the tank into the ladle at casting time. This makes a well- 
mixed and even grade of iron in all the castings and saves con- 



SCIENTIFICALLY DESIGNED CUPOLAS. 357 

siderable time in casting, as the molders are not obliged to wait 
for iron to melt, as is often the case. 

MACKENZIE CUPOLA. 

In Fig. T2 is shown a sectional elevation of the Mackenzie 
cupola, designed by Mr. Mackenzie, a practical foundryman. 
When this cupola was designed the only one in use was the 
common straight one with a limited number of very small 
tuyeres and low charging doors, and it melted very slowly. It 
was the custom in foundries at that time, to put on the blast at 
one or two o'clock and blow all the afternoon in melting a heat. 
Molders generally stopped molding when the blast went on and 
a great deal of time was lost in waiting for iron. To save this 
time and get a few hours' more work from each molder on 
casting days, Mr. Mackenzie conceived the idea of constructing 
a cupola that would melt a heat in two hours from the time the 
blast was put on until the bottom was dropped. He had dis- 
covered that the tuyeres in common use were too small to 
admit blast freely and evenly, and cupolas did not melt so well 
in the center as near the lining and tuyeres. To overcome this 
fault in the old cupola, and admit the blast to the stock evenly 
and freely, a belt tuyere was put in extending around the 
cupola, and to place the belt nearer to the center of the cupola 
at the tuyeres, the lining was contracted or boshed at this 
point. To avoid reducing the capacity for holding molten iron 
below the tuyeres, the lining just above the tuyeres was sup- 
ported by an apron riveted to the cupola casing and the bosh 
made to overhang the bottom, leaving the cupola below the 
tuyeres of the same diameter as before boshing. 

This cupola, when first mtroduced, was known as the two- 
hour cupola, and wrought a great revolution in melting and in 
foundry practice. Heats that had required half a day to melt 
were melted in two hours, the quantity of fuel consumed in melt- 
ing was reduced, the number of molds put up by each molder 
increased, and the cost of producing castings greatly reduced. 

Many of these cupolas are still in constant operation, and for 



358 



THE CUPOLA FURNACE. 
Fig. 72. 




MACKENZIE CUPOLA. 



SCIENTIFICALLY DESIGNED CUPOLAS. 



359 



short heats of one or two hours are probably the most eco- 
nomical melting ones now in use. In long heats the tendency 
of the cupola to bridge at the bosh is so great, that it melts 
slowly toward the end of a heat and is frequently difficult to 
dump, especially if it is a small one. 

We have had much experience in melting in these cupolas. 




and have found that slag and cinder adhere to the lining over 
the tuyeres, and become very hard and difficult to remove, and 
if care be not taken to remove them after every heat it soon 
builds out, as shown in Fig. 'ji, which reduces the melting 
capacity very much, and increases the tendency of the cupola 
to bridge and hang up. The lining should be kept as near 
the shape shown in Fig. ^2 as possible, and all building out 



36o 



THE CUPOLA FURNACE. 



over the tuyeres and bellying out in the melting zone, as far as 
possible, prevented. 

Fig. 74. 




DR. OTTO GMELIN'S CUPOLA. 



In the illustration (Fig. 72) is shown the cupola pit, com- 
monly placed under cupolas when they are set very low for 
hand-ladle work. The outlet to the pit may be placed at the 



SCIENTIFICALLY DESIGNED CUPOLAS. 



361 



front, back, or side of the cupola, as found most convenient for 
removing the dump. 



DR. OTTO GMELIN S CUPOLA. 



The cupola shown in Fig. 74 was invented by Dr. Otto 
Gmelin, of Buda-Pesth, for smelting iron, copper, or other 
metals, and has during the last few years won ground in Austria- 
Hungary, and is now also being introduced in Germany. 

The illustration hardly requires any further explanation, 
considering the simplicity of the principle on which the furnace 
is constructed. Two concentric cylinders of boiler plates with 

Fig. 75. 




I A 



THE TOP PLATE. 



two annular spaces between them, closed at the bottom, and 
open at the top, are placed on a foundation ring of brickwork. 
Cold water enters the annular space at the bottom, and the 
warmed water flows off below the upper edge of the cylinders. 

The interior of the inner boiler-plate cylinder is, says Engi- 
7ieering, made rough, and is covered with fire-clay. The cir- 
cular space between the two cylinders is covered over by a 
cast-iron plate which lies loosely on the top of the two cylin- 
ders. Two circular grooves in the cast-iron top plate maintain 
the two cylinders at the correct distance from each other. 

The outlet of the metal and of the slag takes place through 



362 THE CUPOLA FURNACE. 

tubular boiler-plate connections passing through the water 
space and attached to the inner and outer cylinders. The con- 
struction has lately been considerably simplified and strength- 
ened by making the inner furnace cylinder of a welded tube, 
with tubes for air inlets welded on all in one piece. 

The novelty of the above construction consists chiefly in the 
cooling of the smelting furnace by water without using an air- 
tight water space. The inner cylinder can expand and con- 
tract without any resistance as the temperature in the furnace 
changes, and the consequence is that repairs are hardly ever 
required. The first furnace built upon this principle has now 
been at work daily for the last 2j^ years without ever having 
required any repairs to the boiler plates of the cylinders. The 
smelting operations can therefore also be kept up for any length 
of time without interruption. The energetic cooling of the 
inner smelting cylmder, which takes place with this system of 
furnace, is also stated to afford advantages as regards the sav- 
ing of fuel (equal to from 6 to 8 per cent.) and the decrease of 
burnt metal, as well as the good and equal quality of the castings. 

The above illustrations and description of Dr. Otto Gmelin's 
cupola are taken from a foreign engineering journal, and are 
here given to show what is being done in the way of protecting 
cupola linings with water. 

This theory has been a hobby of a number of founders we 
have met, and it has often been tried in this country and in a 
variety of ways, with but limited success. In one instance we 
recall to mind, gas pipe was closely coiled around the cupola 
at the melting zone, and covered with daubing one or more 
inches thick, and water forced through the coil when the 
cupola was in blast. 

In another, a tank constructed of boiler plate was placed 
around the inside of the cupola at the melting zone, and pro- 
tected by daubing. In both of these experiments it was found 
difificult to keep the pipes and tank filled with water, as the heat 
was so intense that water was driven from them very rapidly 
after melting began, and in one of them the bottom had to be 



SCIENTIFICALLY DESIGNED CUPOLAS. 363 

dropped for fear of collapse of the tank and caisson. But this 
objectionable feature may readily be overcome by making the 
tank large and the inlet and outlet ample for a supply of cold 
water, which was not the case in this instance. 

The doctor appears to have solved this problem by extend- 
ing the water space from the bottom to top of cupola, giving a 
larger body of water to be heated than in the tests referred to. 
But even when this is done the water space must be large and 
the supply admitted at the bottom abundant, or every drop of 
water will be forced from the water space by the heat. 

The experiment referred to, while not perfectly satisfactory, 
so far as keeping the lining cool with water, was sufficiently so 
to convince the advocates of this theory in each case that noth- 
ing could be gained by protecting a lining in this way ; for 
they found by cooling the lining at the melting zone the melt- 
ing capacity of their cupola was reduced and more time was 
required to melt their heat and probably more fuel was con- 
sumed. While this cupola may be a success in foreign coun- 
tries, where slow melting is done, it would hardly prove a suc- 
cess in this country with our present desire for rapid melting, 
and is not likely here to come into use. As for the saving of 
fuel and improved quality of iron, all new cupolas effect these 
results, and they require no further consideration. 

PEVIE CUPOLA. 

In Fig. "jQ is seen the Pevie cupola, designed by Mr. Pevie, 
a practical foundryman of Lowell, Mass. The small cupolas, 
18 to 24 inches, of this design are built square, with square 
corners in the lining, and larger ones are made oblong with 
square corners and 24 to 30 inches wide inside the lining, 
and any increase in the melting capacity of the cupola desired 
is obtained by increasing the length of the cupola in place of 
increasing the diameter, as is done with the round cupolas. 

Blast is supplied on two sides from an inner air chamber, 
through a vertical slot tuyere extending the full length of the 
sides of the cupola. 



364 



THE CUPOLA FURNACE. 

Fig. 76. 




J 
I 



PEVIE CUPOLA. 



SCIENTIFICALLY DESIGNED CUPOLAS. 365 

The object of Mr. Fevie in constructing a cupola upon this 
plan was to supply an equal amount of blast to all parts of the 
stock and to produce even melting. This theory was correct, 
for blast was certainly more evenly distributed to the stock than 
with the small round tuyere then commonly used, and we saw 
excellent melting done in cupolas of this construction in the 
foundry of Pevie Sons, in a small town in Maine (the name 
of which is forgotten), which we visited some twenty years since. 
But in cupola construction an even distribution of blast is not 
the only matter of importance to be considered ; for if it bridges 
and clogs up, the blast cannot do its work, no matter how evenly 
it may be distributed by tuyeres or by the construction of a cu- 
pola, and the peculiar construction of this cupola made the ten- 
dency to bridge very great. It was only by careful management 
that it could in long heats be prevented from bridging, when 
the lining was kept in its original shape, and for this reason it 
never came into general use. We know of only three of them 
at the present time in operation, one at Smithville, N. J., and 
two at Corry, Pa., and the shape of the linings in these cupolas 
has been greatly altered from their original form. 

Stewart's cupola. 

In Fig. '/J is seen a sectional view of a cupola in use at 
the Stewart Iron Works, Glasgow, Scotland. This cupola, 
which is one of large diameter, is boshed to throw the blast 
more to the center of the stock and reduce the amount of fuel 
required for a bed. Blast is supplied from a belt air-chamber 
extending around the cupola, through a row of tuyeres passing 
horizontally through the lining and a second row placed above 
and between the tuyeres of the first row and pointing downwards, 
as shown in the illustration. The object of this second row of 
tuyeres is to increase the depth of the melting zone and increase 
the melting capacity of the cupola per hour. Attached to the 
top of the air-chamber at intervals of about two feet, is placed 
a vertical gas-pipe of two inches diameter, and from this pipe 
four branches of one-inch pipe lead into the cupola, about 



366 



THE CUPOLA FURNACE. 

Fig. 77. 




STEWART'S CUPOLA. 



SCIENTIFICALLY DESIGNED CUPOLAS. 367 

twelve inches apart. The object of these pipes is to supply a 
sufficient amount of oxygen to the cupola above the melting 
zone to consume the escaping unconsumed gas, namely car- 
bonic oxide ( CO), above the melting zone, and utilize it in 
heating and preparing the iron for melting before entering the 
zone. The cupola melts very rapidly, and is said to be the 
best melting one in Glasgow. But it is very doubtful if the one- 
inch gas- pipe tuyeres contribute anything towards the rapid 
melting, for it is absurd to suppose that one-inch openings 
placed twelve inches apart vertically, and two or more feet 
apart around the cupola, would supply a sufficient amount of 
oxygen to fill a large cupola to such an extent as to ignite 
escaping carbonic oxide in the center of the cupola. While 
they might supply oxygen for combustion of carbonic oxide nea"- 
the lining, we do not think they would admit a sufficient amount 
to be of any practical value in melting, even if they admitted a 
volume of blast equal to their capacity when placed in the lin- 
ing. This they do not do, for they are frequently clogged by 
fuel or iron, filled with slag from melting of the lining, and as a 
lining burns away the ends of the pipes are heated and fre- 
quently collapse at the ends, and it is almost impossible to keep 
them open during a heat, or to open many of them after a heat 
is melted. The rapid melting in this cupola is probably due to 
the arrangement of the first and second rows of tuyeres and the 
shape given to the inside of the cupola, which is excellent for 
cupolas of large diameter. 

THE GREINER PATENT ECONOMICAL CUPOLA. 

In Fig. 78 is shown the Greiner cupola, for which the follow- 
ing claims are made : 

In placing the Greiner Patent Economical Cupola, before the 
foundrymen and steel manufacturers in this country, we have 
the advantage of the splendid results already obtained with this 
cupola in Europe, where more than three hundred are in daily use. 

The adoption of the Greiner system of melting iron there has 
met with the most satisfactory results. In no case has the sav- 



368 



THE CUPOLA FURNACE. 



ing of fuel been less than twenty per cent., and in some instan- 
ces it has reached forty and even fifty per cent. 

The novelty of the invention consists in a judicious admission 
of blast into the upper zones of a cupola, whereby the combus- 

FiG. 78. 




THE GREINER PATENT ECONOMICAL CUPOLA. 

tible gases are consumed within the cupola and the heat utilized 
to pre-heat the descending charges, thereby effecting a saving 
in the fuel necessary to melt the iron when it reaches the melt- 
ing zone. 

Considerably more space was given to this cupola in the first 
edition of this work, where it may be seen ; but as we do not 
know of a single one of them in operation in this country, we 



SCIENTIFICALLY DESIGNED CUPOLAS. 369 

devote the space to more important matter. The same prin- 
ciple may be seen more fully illustrated in the sectional view 
of the Stewart Cupola (Fig. "JT). 

STEAM JET CUPOLAS. 

The arrangement of pipes of the Greiner cupola recalls to 
mind the arrangement of pipes, a variety of which we have 
seen, for admitting steam jets at various points to cupolas for 
the purpose of improving the melting or the quality of the 
iron. This mode of melting has been thoroughly tried in this 
country in years past and a number of patents have been taken 
out for it here and in Canada, none of which have ever come 
into general use, although great claims have been made for 
them both as to economy of fuel and improvement of quality 
of iron. The inventor of one of them, which we saw in opera- 
tion some twelve years ago, went so far as to claim he could 
from a cupola produce an iron having all the qualities of mal- 
leable iron. This device we found upon investigation to con- 
sist of putting a jet of steam into the cupola at the tuyeres with 
the blast, which only amounted to putting that amount of water 
into the cupola, which, so far as we could see, had no effect on 
the qualiy of iron, and certainly no malleable iron was pro- 
duced in the heat we saw melted. 

We made a series of experiments in melting in a cupola with 
steam with and without blast some twenty-five years ago. A 
detailed account of these experiments is not necessary, for 
they proved a complete failure so far as saving fuel, making 
hotter iron, or improving the quality of the iron ; although 
we were under the impression at the time that some improve- 
ments had been effected, but these, like many results obtained in 
experiments, were deceptive and due rather to careful manage- 
ment of the cupola than to any benefit derived from the steam. 
Since making these experiments we have met a number of men 
who have experimented in this direction, among them the late 
Thomas Glover, who, when foreman of the large foundry of 
Morris, Tasker & Co., made extensive experiments with steam 
24 



370 THE CUPOLA FURNACE. 

in their large cupolas, using wet and super-heated steam, and 
putting it into the cupola at the tuyeres and above and below 
the melting zone. Mr. Glover kept an accurate record of these 
experiments, a copy of which he ofifered to furnish for this 
work, but the experiments were made years ago, and when he 
came to look for the record it could not be found. That the 
results of these experiments were not satisfactory is shown by 
the fact that Morris, Tasker & Co. did not continue the use of 
steam in their cupolas, and when Mr. Glover engaged in busi- 
ness for himself, as the firm of Glover Bros., he did not apply 
steam to their cupolas. 

From what we have observed in melting with wet and super- 
heated steam we have concluded that the passing of steam into 
a cupola amounts only to the placing of a certain amount of 
water or moisture in it, and this may be accomplished in a more 
economical way than with steam. By placing a small water 
jet at each tuyere the water may be atomized and carried into 
the cupola with the blast, and by placing one or two gunny 
bags over the inlet of a blower, and keeping them wetted with 
water, moisture may be added to the blast and carried into the 
cupola. But probably the best way to accomplish this is to 
wet coke before charging. Years ago it was the common prac- 
tice of founders to let their coke lie out in the weather, and in 
dry weather to wet it with a few bucketfuls of water before charg- 
ing, upon the theory that wet coke made hotter iron than dry. 
But since the discovery by some one that about one-third more 
coke is required to smelt iron in a blast furnace on a wet day 
when the atmosphere is full of moisture, than on a dry day, 
this theory has been abandoned by founders and coke carefully 
housed. 

While this discovery may be correct in a blast furnace, which 
we very much doubt, we think that a careful" and prolonged 
test will demonstrate that the reverse is the case, and that 
more fuel is required on a dry day than a wet one. For a gas 
may be made from water having a sufificient number of heat- 
producing units to melt iron. This being the case, why should 



SCIENTIFICALLY DESIGNED CUPOLAS. 37 1 

not a blast saturated with moisture produce a greater amount 
of heat than a dry one? But whether or not this theory be 
correct as regards a blast furnace, it is certainly not so in a 
cupola, for no founder ever thinks of placing more fuel in his 
cupola on a wet day than on a dry one, and always has hotter 
iron on a wet, murky or foggy day than on a dry, clear one, 
with the same amount of fuel. 

From our observation in the use of steam in a cupola, we 
are of the opinion that, as good results may be obtained from 
steam generated in a cupola in any of the ways outlined as 
from steam generated in a boiler and conveyed to it by pipes, 
and that no great benefit can be derived from steam in either way. 

JUMBO CUPOLA. 

In the accompanying illustration. Fig. 79, is shown a sectional 
elevation of the large cupola known as Jumbo, in use in the 
foundry at Abendroth Bros., Port Chester, N. Y., to melt iron for 
stove plate, sinks, plummers' fittings, soil pipe and other light 
castings, all requiring very hot fluid iron. The cupola, which 
was constructed for the purpose of melting all the iron required 
for their large foundry in one cupola, is of the following dimen- 
sions : Diameter of shell at bottom to height of 24 inches, 7 feet 
6 inches ; diameter in body of cupola, 9 feet ; taper from large to 
small diameter, 5 feet 6 inches long; diameter of stack, 6 feet; 
taper from cupola to stack, 6 feet long ; height from bottom 
plate to bottom of taper to stack, 20 feet; height to bottom of 
charging doors, 18 feet; two charging doors placed in cupola 
on opposite sides. Wind box inside the shell extending around 
the cupola, 5 feet 6 inches by 9 inches wide. Height of tuyeres, 
first row, 24 inches; second row, 36 inches; third row, 48 
inches. Size of tuyeres, first row, 8X5 inches ; second row, 
6X4 inches; third row, 2X2 inches. Number of tuyeres in 
each row, 8 ; total number of tuyeres, 24. Slag hole, 17 inches 
above iron bottom, 1 1 inches above sand bottom. Two tap 
holes. Lining, 18 inches thick; over air belt, 9 inches. Di- 
ameter of cupola at bottom, inside the lining, 4 feet 6 inches. 
Diameter above taper, 6 feet. Cupola supplied with blast by 
No. 6 Baker blower. 

It is charged as indicated in the table as follows: 



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SCIENTIFICALLY DESIGNED CUPOLAS. 



373 



Three hundred and fifty pounds of limestone are placed on 
each charge of iron, except the last charge, and the slag hole 
opened after the blast has been on about three-quarters of an 
hour and permitted to remain open during the rest of the heat. 

Fig. 79. 




JUMBO CUPOLA. 



The sprues, gates and foundry scrap are not milled before 
charging, and the large amount of limestone placed on each 
charge is required to liquefy the quantity of sand charged into 
the cupola on the scrap, and prevent clogging and bridging of 



► 



374 



THE CUPOLA FURNACE, 



the cupola. Sixty tons of iron have been melted in this cupola 
in four hours from the time the blast was put on until the 
bottom was dropped. This cupola is still in use, and is one of 
the most rapid melting and economical cupolas in use at the 
present time. 

THE CRANDAI.L IMPROVED CUPOLA WITH JOHNSON PATENT CENTER 
BLAST TUYERE. 

In Fig. 80 is shown the above-named cupola and tuyere. 
The cupola is designed with a view of getting a more efficient 
action of the blast than is possible to attain with the methods 
now in general use, and the manufacturers make the follow- 
ing claims for it : The experiments made in this new de- 

FlG. 80. 




THE CRANDAI.L IMPROVED CUPOLA WITH JOHNSON 
PATENT CENTER BLAST TUYERE. 

parture have finally led to a very simple and durable con- 
struction, which we place before the foundrymen and request 
that they make a thorough investigation of it. It is a well- 
known fact that the matter of forcing blast to the center of a 
cupola and obtaining a complete combustion of fuel at that 



SCIENTIFICALT.Y DESIGNED CUPOLAS. 375 

point, has been to many a puzzle, and various means have been 
tried to accomphsh this end. But it has been found in all 
cases, that a large portion of the blast when taken in at a high 
pressure through outside tuyeres, in striking the fuel is forced 
back against the brick lining, cutting it out very rapidly just 
above the tuyeres and then escaping up along the brick wall, 
doing no good, thereby requiring a greater volume of blast to 
melt the same amount of iron than is used when the blast is 
taken in at the center of the cupola. In the illustration (Fig. 
80) is clearly shown the general arrangement. 

The air, instead of being forced into the cupola furnace from 
the outside, is applied from the inside by means of a center 
blast tuyere attached to the under side of the bottom plate. 
This tuyere terminates at about the same height as outside 
tuyeres, and a continuous annular opening is formed for the 
blast by putting on a loose section of pipe and spacing it apart 
by means of pins that can be varied in height, so as to get any 
desired opening. On top of this loose section a cap is set ; also 
spaced apart from it by means of pins, so that a second open- 
ing is formed for the blast to enter, and by taking in more air 
at this point the carbonic oxide, which would otherwise go to 
waste, is changed into carbonic acid gas, forming the whole in- 
terior into a melting zone, insuring complete combustion. Both 
the loose pipe section and the cap can be removed to have the 
lining of them repaired. The horizontal part of the center 
blast pipe has an opening at the elbow which enables it to be 
cleaned out, in case any obstructions should fall through the 
tuyere opening above. The drop doors close over this tuyere 
and can be opened without in any way deranging it. No belt 
air-chamber is required, as the tuyere may be connected direct 
to the main blast pipe ; but in cases where such air-chambers 
already exist, the center blast tuyere may be attached to them 
without in any way disarranging the blast pipe. We would 
draw special attention to the fact that but little expense need 
be incurred in making this change outside of the price charged 
for the center blast tuyere and piping. 



3/6 THE CUPOLA FURNACE. 

Claims are made as follows : 

1st. A saving in brick lining. 

2d. A saving in fuel. 

3d. More rapid melting with less volume of blast. 

4th. A more uniform temperature of iron than can be at- 
tained by the outside tuyere. 

Note. — A letter sent to the manufacturer of this cupola in 
regard to its present range of usefulness failed to bring any 
reply, and it has probably been consigned to the fate predicted 
for the bottom tuyere in the first edition of this work, for we do 
not know of a single one of these cupolas being in use at the 
present time. 

BLAKENEY CUPOLA. 

In Fig. 81 is seen a sectional view of the Blakeney cupola 
furnace, the following history and description of which are 
furnished by The M. Steel Co., Springfield, Ohio. 

By the Blakeney cupola furnace, the air is so distributed or 
projected into the furnace as to produce a uniform heat, giving 
the iron a uniform strength for all kinds of castings. The 
features peculiar to it are as follows : 

The introduction of a combination of curved tuyeres or chutes 
placed upon the wall or lining of the cupola, and forming a 
part of the wall, a proper distance from the bottom, and nearly 
surrounding the inner and outer sides of the wall. The tuyeres 
are made of cast-iron and in sections for convenience of hand- 
ling. A blank space is left in the rear of the cupola two feet 
wide, through which the slag is blown, if required. 

A chamber or base extending around the cupola and enclos- 
ing the space in which the air is conducted to the tuyeres. 
The bottom of this chamber, made irregular in form, hollows 
at suitable intervals to allow the metal to flow to the escape 
openings, in case it overflows through the tuyeres. The open- 
ings are closed with fusible plugs of lead or other material, to 
be melted out by the molten metal. 

The blast is conducted to this cupola through one pipe, and 
striking the blank space sidewise in rear of chamber, passes all 



SCIENTIFICALLY DESIGNED CUPOLAS. 



17\ 



around through the curved tuyeres into the center of the fur- 
nace, the blast striking into the cupola every seven-eighths of 
an inch horizontal, and 3^ inches perpendicular, or according 
to diameter of cupola. 

As a producer of a uniform grade of iron for the purpose of 
casting car-wheels, it is just what is needed for the different 
grades of iron to prevent chill cracking. 

This cupola, with its many superior advantages, has also 
rows of shelves bolted to the shell four feet apart up to the 

Fig. 81. 




SECTIONAL VIEW OF BLAKENEY CUPOLA FURNACE. 



top of the charging door, so that it will not be necessary to 
tear out any of the lining except that which is burned out. 
These cupolas liave run eighteen months with heavy heats 
without being relined. 

To prevent sparks from being carried out of the stack, it is only 
necessary to provide sufficient room in the stack for the blast 
to expand, after escaping from the cupola, and lose its lifting 
force, when the sparks will fall back in the cupola and be con- 



378 THE CUPOLA FURNACE. 

sumed. This may be done by constructing the stack casing of 
the same diameter as the cupola casing, and lining it with a 
thin lining of four-inch fire-brick supported by angle iron, so 
that the cupola lining may be removed or repaired without dis- 
turbing the stack lining. Cupolas constructed in this way, 
when the stack is of proper height, do not throw out sparks. 
When it is not desirable to have a very high stack, the enlarged 
stack shown in Fig. 83 may be used. The first cost of a stack 
of this kind is a little greater than that of a contracted one, 
but when properly constructed and lined, will last the life of a 
cupola. In fact we never knew one, if properly lined when 
constructed, requiring to be relined or repaired, and the saving 
effected by preventing damage to roofs, lumber, flasks, etc., 
from sparks will soon pay for the extra cost of construction. 
The objection usually made by foundrymen to large stacks is 
that they do not give sufficient draught for lighting up. This 
may be the case when the top of the stack is only a few feet 
above the charging door, but when given a proper height for 
arresting sparks there is always suflficient draught for lighting 
up. There are many cupolas constructed upon this plan in 
use at the present time, and they give better satisfaction than 
those with contracted stacks. 



CHAPTER XXII. 

SPARK CATCHING DEVICES FOR CUPOLAS. 

FOUNDRYMEN whose plants are located in closely built-up 
neighborhoods are very much annoyed by sparks thrown out 
of their cupolas lighting upon the roofs of adjoining buildings 
and setting them on fire. In some cases they have on this 
account been compelled to move their plants from towns and 
cities to the suburbs. Many plans have been devised and tried 
for arresting these sparks ; one of the oldest and most efficient 
of which is the design shown in Fig. 82. This arrangement was 
devised when the old-fashioned cupolas with brick stacks were 
in vogue, and was generally put up in such cases where cupola 
sparks were very objectionable. It consisted in constructing 
the stack upon an iron plate supported b)' iron columns, on a 
level with the top of the cupola. The end of this plate ex- 
tended over the top of the cupola, with an opening in the plate 
equal to the inside diameter of the cupola, and on the plate 
was put a short stack, in which was placed the charging door, 
the top of which was arched over toward the main stack, with 
which it connected on the side. 

Any sparks that arose from the cupola were thrown into the 
bottom of the main stack by the arch in the direction indicated 
by the arrows and were removed when cold, as often as the 
bottom of the stack filled up to such an extent as to interfere 
with the arrest of the sparks. 

This arrangement was very efTective in arresting sparks, but 
was not found to be a very convenient one for attaching to our 
modern cupolas, and numerous other plans have since been 
devised and used. 

In Fig. 83 is seen a more modern spark-arrester than the one 

( 379 ) 



.380 THE CUPOLA FURNACE. 

just described. In this device, the casing is cut in two at the 







SPARK CAICHER IN OLD bTYLE CUPOLA. 



bottom of the charging door and an iron plate or ring placed 



SPARK CATCHING DEVICES FOR CUPOLAS. 38 1 

Fig. 83. 




SPARK CATCHING DEVICE IN MODERN CUPOLA. 



382 THE CUPOLA FURNACE. 

upon the top of the cupola casing, where it is supported by 
the casing and cast-iron brackets riveted or bolted to it on the 
outside. The inside of the plate or ring generally covers the 
top of the cupola lining to protect it when charging the stock, 
and the outside extends over the cupola casing from six to 
twelve inches. On this plate the stack casing, which is of 
larger diameter than the cupola casing, is placed and lined 
with a thin lining. The spark-arresting device consists in 
making the stack larger than the cupola, so that the blast loses 
its force when it emerges from the cupola and enters the stack, 
and the sparks carried out of the cupola fall back into it before 
reaching the top of the stack. The extent to which the stack 
should be enlarged to be effective in arresting sparks depends 
upon the height of it; low stacks requiring to be of a larger 
diameter than high ones. 

In this illustration is shown a very neat arrangement for sup- 
plying blast to a cupola when a belt air-chamber riveted to the 
cupola shell is not used. The main blast-pipe AA, which 
encircles the cupola, is placed up out of the way, in catching 
iron or removing large ladles. The branch pipes are cast in 
one piece and tightly bolted or riveted to the main pipe and 
cupola casing, to prevent the escape of blast. The peep holes 
BB are cast in the pipe, and close with a tight-fitting swing cap 
and latch. 

RETURN FLUE CUPOLA SPARK- CATCHER. 

In Fig. 84 is shown a device designed by John O'Keefe, 
Superintendent of Perry & Co.'s Stove Works, Albany, N. Y., 
for catching sparks and saving fuel. The foundry of the firm 
in which this device was constructed, was located on Hudson 
St., in a closely built up part of the city, and they were very 
much annoyed by sparks from their cupola setting fire to roofs 
of buildings in the vicinity, and it became necessary to prevent 
sparks escaping or move their foundry. A number of devices, 
such as hoods, etc., were tried, but none of these proved effec- 
tive, and a return flue was constructed. The arch or dome A was 



SPARK CATCHING DEVICES FOR CUPOLAS. 
Fig. 84. 



383 




RETURN FLUE CUPOLA SPARK-CATCHER. 



384 THE CUPOLA FURNACE. 

thrown across the cupola stack above the door, and the flue B 
led out of the cupola just below the dome and down to the 
foundry floor, from which point it returned to the stack above 
the dome. When the cupola was in blast, waste heat from the 
cupola struck the dome and was thrown back upon the stock 
in the cupola, or was forced down through the flue B and re- 
turned to the cupola stack through the flue C above the dome. 
When the cupola was put in blast it was found that so large 
an amount of heat and gas escaped from the door that the 
cupola could not be charged when in blast, and it became 
necessary to make a small opening through the dome to per- 
mit part of it to escape. Had the cupola been of a size to 
admit of all the stock being charged before the blast was put 
on and the door closed, during the heat, there is no doubt con- 
siderable fuel might have been saved, and faster melting done. 
But as it was, no fuel was saved, and there was no perceptible 
change in the time required to melt a heat. The device was 
eff"ective in preventing the escape of sparks and small pieces 
of fuel from the stack, for they were all thrown back into the 
cupola or deposited in the bottom of the flue, from which they 
were removed through the openmg D at the bottom of the 
flue, as frequently as found necessary. 

OTHER SPARK CATCHING DEVICES. 

Another device for arresting sparks is to place a half circle 
fire-brick arch opened at both ends on the top of the stack, 
making its total length and breadth equal to the outside 
diameter of the stack. This plan arrests the sparks in their 
upward course and some of them fall back into the cupola, 
but many are carried out at the ends of the arch by the blast 
and fall upon the foundry roof, and on windy days may be 
carried to adjoining roofs. 

Iron caps or hoods are also placed one or more feet above 
the top of cupola stacks to "arrest sparks ; but they, like the 
arch, only arrest the sparks in their upward flight and throw 
many of them down upon the foundry or scaffold roof. 



SPARK CATCHING DEVICES FOR CUPOLAS. 385 

Another plan for preventing the escape of sparks is to sus- 
pend an iron disk of a few inches smaller diameter than the 
stack in the stack near the top. The sparks strike this disk 
and are thrown back into the cupola. But this device cannot 
be used in contracted stacks with a strong blast, and in large 
ones the cohesive properties of the iron are soon destroyed by 
the heat and gases of the cupola, and if not frequently replaced 
there is danger of it breaking from the jar in chipping out the 
cupola, and falling upon the melter. 

THE BEST SPARK- CATCHING DEVICE. 

The cause of sparks being thrown from a cupola is the 
strong blast forced into the cupola at the tuyeres, which 
carries small pieces of fuel out at the top of the stack during 
the heat, and large pieces near the end of a heat, when the 
stock is low in the cupola and the blast passes through it more 
freely. The lifting power of the blast is increased by confining 
it in a contracted stack, and good sized pieces of fuel may be 
thrown several feet above the top of a small stack ; but the in- 
stant the blast escapes from the top of the stack it expands 
and its lifting power is lost, and sparks or pieces of fuel fall by 
their own weight and may in their descent be carried to some 
distance by a strong wind. To prevent this, enlarge the diam- 
eter of the stack to an extent that will admit of the blast losing 
all of its spark-lifting power before reaching the top of the 
stack. Another plan of preventing sparks setting fire to adjoin- 
ing buildings is to extend the stack up to a height of one hundred 
feet. The sparks then lose the greater part of their fire while 
descending and are not so dangerous. This great height of 
stack also presents the advantage of carrying all gases from the 
cupola to so great a height that they are not objectionable in 
closely built up towns and cities. This plan has been adopted 
by the Brown and Sharpe Manufacturing Co., Providence, R. T. 

CUPOLA HOODS. 

There are a variety of cupola hoods designed to be spark 

25 



386 THE CUPOLA FURNACE. 

arresters, by having the sparks strike the hood and fall back 
into the cupola. One of the best of these hoods is the crossed 
arch open at both ends constructed of boiler plate and lined 
with fire brick. This hood is very substantial, and when prop- 
erly lined lasts as long as the cupola stack. Another hood is 
constructed of a round plate of boiler plate of the diameter of 
the cupola, and supported on iron legs or braces from 12 to 18 
inches above the top of the stack. Still another hood is the 
double hood. This is constructed of boiler plate and consists 
of a ring of the diameter of the cupola on the outside, and a 
little smaller than the diameter of the lining on the inside. 
This ring is supported on legs or braces. Eight to ten inches 
above the ring is placed a crown-shaped plate, of a less diam- 
eter than that of the cupola or ring. In this way two or three 
rings are sometimes placed above each other, each ring being 
smaller than the one below it. The object of this construction 
is to have the sparks strike the crown, and be thrown down 
upon the rings or shelves from which they fall upon the foundry 
roof. Years ago almost every cupola was provided with one 
of these hoods, but of late years very few of them have been 
placed upon cupolas, for it has been found that they prevent 
the sparks from being thrown high in the air, where they may 
be cooled by falling, but throw them down upon the roof 
while full of fire and thus increase the danger of setting fire to 
the foundry or adjoining building. Another objection to hoods 
is, that they become covered with a very heavy coating of 
oxides, which is sometimes loosened by the jar in chipping out 
and falls upon the melter. 



I 



CHAPTER XXIII. 



CUPOLA SCRAPS. 



BRIEF PARAGRAPHS ILLUSTRATING IMPORTANT PRINCIPLES. 

Make a heat, take a heat, make a cast, make a mould, run a 
melt, casting, moulding, are all terms used in different sections 
of the country to indicate the melting of iron in a cupola for 
foundry work. 

When iron runs dull from a cupola, draw all the melted iron 
off at once and prevent the newly melted iron being chilled by 
dropping into dull iron in the bottom of the cupola. 

When slag flows from a tap-hole with a stream of iron, when 
the iron is not drawn ofif too close, it is due to too much pitch 
in the sand bottom. 

The formation of slag in a spout is due to poor material used 
in making up the spout. 

Some foundrymen do not seem to know what hot iron is, for 
they call all kinds of B. S. hot iron if it will run out of the 
ladle. 

The cutting-out of the spout lining in holes by the stream of 
molten iron is due to a deficiency of cohesive properties in the 
lining material when heated to a high temperature. 

When a tap-hole is closed up with slag and cannot be kept 
open, the slag is generally produced by the melting of the ma- 
terial used in making up the front and tap-hole. Slag made in 
the cupola flows from the tap-hole without clogging it. 

A little sand or clay-wash added to the front and spout 
material will generally correct the deficiencies in the material 
and save the melter a great deal of trouble with his spout and 
tap-hole. 

In a spout with a broad flat bottom the stream takes a differ- 

( 387 ) 



388 THE CUPOLA FURNACE. 

ent course at every tap, the spout soon becomes clogged with 
cinder and iron, the molten iron flows in all directions, and the 
spout looks like a small frog pond with patches of scum. 
Make the bottom of the spout narrow and concentrate the 
stream in the center. 

If the sand bottom does not drop readily when the doors are 
dropped, there is too much clay in the bottom material. Mix 
a little sand and cinder riddled from the dump with it, or some 
well-burnt moulding sand. 

A hard rammed bottom causes iron to boil in a cupola the 
same as a hard rammed mould, and is frequently the cause of 
a bottom cutting through. A bottom should be rammed no 
harder than a mould. 

Wet sand in a bottom not only causes iron to boil, but 
hardens it. Bottom sand should be no wetter than moulding 
sand when tempered for moulding. 

Exclusively new sand should not be employed in making a 
bottom. The old bottom with a few shovelfuls of sand riddled 
from the gangways makes the best bottom material. 

Often a melter " don't know " why the cupola is working 
badly, because, if he knew, he would be discharged at once for 
carelessness. 

A bad light-up makes a bad heat. The bed must be burned 
evenly, or it will not melt evenly. 

If the wood is not all burned up before iron is charged, the 
wood smokes and the melter cannot see where to place the 
fuel and iron when charging. Never use green wood for light- 
ing up. When green wood is used for lighting up, the bed is 
frequently burned too much before the wood is burned out and 
the cupola is free of smoke. 

Don't burn up the bed before charging the iron. When the 
fuel is well on fire at the tuyeres and the smoke is all burned 
off, put in the front, close the tuyeres and charge the iron at 
once. 

If anything happens to delay putting on the blast after the 
fire is lighted, do not let that delay charging the iron, for the 



CUPOLA SCRAPS. 389 

bed will last longer with the iron on it than it will with it off. 
Charge the iron as soon as the bed is ready for charging ; close 
the front and tuyeres and open the charging door to stop the 
draught, and the cupola may be left to stand for hours and as 
good a heat be melted as if no delay had occurred. 

A melter who burns up his tapping bars so that two have to 
be welded together to make one almost every heat, don't know 
how to put in a front or make his bod stuff. 

The amount of fuel wasted every year in the United States 
by the use of high tuyeres in cupolas is sufficient to make a 
man very rich. 

A new cupola always effects a greaf saving in fuel, but it is 
often hard to find the fuel (saved) at the end of the year. A 
little more practical knowledge in managing the old cupola will 
often enable the foundryman to find the fuel saved and price of 
the new cupola besides. 

Never run a fan in its own wind merely to show a high pres- 
sure on the air-gauge. 

The volume of blast supplied to a cupola should be regulated 
by the speed of the blower and not by the size of tuyeres. 

That old "no blast" story of the melter has had its day 
among practical foundrymen. 

The air-gauges in use at the present time for showing the 
pressure of blast on a cupola are an excellent thing to prevent 
a poor melter from claiming he has no blast and blaming a bad 
heat on the engineer, for the gauge always shows a higher 
pressure of blast when the cupola is bunged up from poor 
management. 

High tuyeres in a cupola are an inheritance left us by our 
forefathers in the foundry business, of which we have never 
got rid. 

The only general improvement made in tuyeres in the past 
fifty years has been in increasing them to a size that will admit 
the blast freely to a cupola. The only local improvement has 
been in placing them lower. 

Molten iron should be handled in a ladle and not held in a 



390 THE CUPOLA FURNACE. 

cupola. Nothing is gained by holding iron in a cupola to keep 
it hot. 

" I will let that go for to-day, and to-morrow I will take more 
time and fix it right," is a remark frequently made by melters. 
That kind of work is often the cause of a very bad heat. 

Pig-iron melts from the ends, and the shorter it is broken the 
quicker it will melt. 

Tin-plate scrap may be melted in a cupola the same as cast- 
iron. It throws ofT sparks from the tap-hole and spout similar 
to hard cast-iron. 

The fins on castings made from tin-plate scrap must be 
knocked ofT with the rammer, for the castings are too hard and 
brittle to be chipped or filed. 

•The loss of metal in melting tin-plate scrap in a cupola is 
not so great as in melting iron when melted with a light blast, 
but the loss may be as great as 25 per cent, when melted with 
a very strong blast. 

The cost of melting iron in a cupola is about two dollars 
per ton. 

The cost of melting tin-plate scrap in a cupola is from three 
to four dollars per ton. 

Galvanized sheet-iron scrap, when melted with tin-plate 
scrap, reduces the temperature of the molten metal to such an 
extent that it cannot be run into moulds. 

Anthracite coal picked from the dump of a cupola will not 
burn alone in a stove or core oven furnace, and it is very doubt- 
ful if it produces any heat when burned with other coal in a 
cupola. 

Lead is too heavy and penetrating when in a fluid state to 
be retained in a cupola after it has melted. The ladle should 
be warmed and the tap-hole left open when melting this metal 
in a cupola. 

The best lining material for a cupola in which tin-plate scrap 
is melted is a native mica soap-stone. 

The sparks that fly from a stream of hard iron at the tap- 
hole and spout are the oxide of iron. They are short-lived 
and burn the flesh or clothing very little. 



CUPOLA SCRAPS. 39 1 

The sparks from a wet tap-hole or spout are molten iron, 
and burn wherever they strike. 

We have probably chipped out, daubed up and melted iron 
in a greater number of cupolas and in more different styles of 
cupola than any melter in the United States, and in heats that 
require from two or three hours to melt, and we have found 
that 8 pounds of iron to i pound of best coke ; 7 pounds of iron 
to I pound of best anthracite coal ; 6 pounds of iron to i pound 
of hard wood charcoal ; 4 pounds of iron to i pound of gas- 
house coke, is very good melting. We have done better than 
this in test heats, but do not consider it practicable to melt iron 
for general foundry work with less fuel than stated above. 

The best practical results for melting for general foundry 
work are obtained from 6^ to 7 pounds of iron to i pound of 
coke ; 5 to 6 pounds of iron to i pound of hard coal ; 4 to 5 
pounds of iron to i pound of hard wood charcoal ; 3 pounds of 
iron to i pound of gas-house coke. 

A less per cent, of fuel is required in long heats than in short 
ones, for, as a rule, three to one is charged on the bed and ten 
to one on the charges, and the greater the number of charges 
melted, the less per cent, of fuel consumed. 

Ten pounds of iron to one of coke are melted at the Home- 
stead Steel Works, in cupolas that are kept in blast night and 
day for six days. 

Less fuel is generally required to melt iron in the foundry 
office than is required to melt it in a cupola. 

Use a light blast when melting with charcoal or gas-house 
coke. 

If you go into the foundry when the heat is being melted and 
find the tap-hole almost closed, the spout all bunged up and 
the melter picking at the spout with a tap-bar and running a 
rod into the tap-hole a yard or so in his efforts to get the iron 
out, and remark to him: "You are having some trouble with 
your cupola to-day," he will say : " Yes, we have some very 
bad coke to-day, sir; that last car is poor truck;" or, "We are 
melting some dirty pig or scrap to-day, sir." He never thinks : 
" We have a very poor melter to-day, sir." 



392 THE CUPOLA FURNACE. 

At the first meeting of the American Association of Foundry- 
men, held in Philadelphia, May 12, 13, 14, 1896, one of the 
delegates was Mr. C. A. Treat, a good-sized practical foundry- 
man weighing over 300 pounds, and representing the C. A. 
Treat Mfg. Co., Hannibal, Mo. After the meeting had effected 
a permanent organization, transacted all its business and was 
about to adjourn, Mr. Treat arose and in his quiet way re- 
marked "Gentlemen: Since we have formed an organization 
of foundrymen for our mutual benefit, don't you think it would 
be a good idea for foundrymen to stop lying to each other? " 
The burst of laughter that followed this remark was loud and 
long. It would be a great relief to many foundrymen if some 
foundrymen would take the hint and stop lying about the 
large amount of iron melted with a small amount of fuel, fast 
melting, etc. 

A few years ago, a foundryman who was about to publish a 
work on foundry practice, being desirous to obtain some reli- 
able data on cupola practice, had several hundred blanks printed 
and sent to foundrymen in different parts of the country, with 
the request that they fill in the amount of fuel placed in the bed 
and charges, the amount of iron placed on bed and charges, 
diameter of cupola, height of tuyeres, etc. He was surprised 
at the reports received in reply. Many of them showed that 
the men who filled in the blanks either knew nothing at all 
about a cupola, or, knowing the report was to be published, 
were desirous of making an excellent showing of cupola work in 
their foundries, and in many of the reports the cupola was filled 
with stock in such a way that not a pound of iron could have 
been melted in a cupola charged as indicated in the formula. 
In some cases, the amount of fuel placed in the bed was not 
sufficient to fill to the tuyeres a cupola of the diameter given ; 
in others, the fuel placed in the charges was not sufficient to 
cover the iron and separate the charges ; and it was only after 
pointing out these mistakes and returning the reports for cor- 
rection, in some cases two or three times, that they were put in 
any kind of shape for publication. 



CUPOLA SCRAPS. 393 

Some fifteen years ago, when we took a more active part in 
melting than at the present time, and occasionally published 
an account of heats melted, we were repeatedly criticised in 
print by some would-be melters, who were melting anywhere 
from ten to twenty to one, for using too large a quantity of 
fuel, and sometimes were invited to come to their foundries 
and get a few points on melting before publishing another work 
on the subject. We have never learned of any of our critics on 
the fuel question becoming prominent in foundry matters or 
rich in the foundry business, and presume they have all saved 
their employers such a large amount of fuel in melting that 
they have been placed upon the retired list with half pay. 

The heats published at that time were the best that could 
be melted in the cupolas described, and the amount of fuel 
consumed was generally about seven to one with hard coal and 
eight to one with best Connellsville coke. The foundrymen 
who at the present time melt heats of the same size in cupolas 
of the same diameter, with a less per cent, of fuel, are like 
-angels' visits, few and far between. 



CHAPTER XXIV. 



BLAST PIPES AND BLAST. 



BLASr PIPES. 



In constructing a cupola, one of the most important points 
to be considered is the construction and arrangement of blast- 
pipes and their connection with the cupola, for the best con- 
structed cupola may be a complete failure through bad arrange- 
ment of pipes and air-chambers. 

Not many years ago it was a common practice of foundry- 
men to place blast-pipes underground. The main pipe was 
generally made square and constructed of boards or planks 
spiked together, no care being taken to make air-tight joints, 
and the escape of blast was prevented by ramming sand or clay 
around the pipe when put in place. Connections from the 
main pipe to the cupola were made by means of vertical cast- 
iron pipes to each tuyere, as shown in Figs. 'J2 and 73. The 
iron pipes were generally constructed with square elbows and 
ends, and the tuyere pipes were placed over an opening in the 
top of a branch of the main pipe on each side of the cupola. 
The square turns and ends of the pipe greatly reduced the force 
of the blast, and the capacity of the pipe was frequently reduced 
by water leaking into it, or a partial collapse of the pipe, and 
the volume of blast delivered to a cupola was very uncertain 
even when the pipes were new, and could not be depended 
upon at all when the pipes became old and rotten. Iron pipes 
arranged in this way were also a source of continual annoyance 
and uncertainty from water or iron and slag from the tuyeres 
getting into them and reducing their capacity for conveying 
blast. This way of arranging cupola pipes has generally been 
abandoned, and they are now commonly placed overhead or 

(394 ) 



BLAST PIPES AND BLAST, 395 

up where they are least liable to injury and may be readily ex- 
amined to see that there is no leakage of blast from a pipe. 

Blast-pipes may be made of wood, tin plate, sheet iron, cast 
iron, or galvanized iron. Wooden pipes shrink and expand 
with changes of weather and moisture in the atmosphere, and it 
is almost impossible to prevent the escape of blast from such 
pipes. Tin and sheet-iron pipes, when placed in a foundry, are 
very rapidly rusted and destroyed by steam and gases escap- 
ing from moulds and the cupola, if not thoroughly painted out- 
side and in. Cast-iron pipes are heavy, difficult to support in 
place, liable to break when not properly supported, or leak at 
the joints, and the best for foundry use are those made of gal- 
vanized iron. In constructing pipes of this material, an iron of 
a proper gauge for the size of pipe should be selected, and their 
shape should, whenever possible, be round, for round pipes are 
more easily constructed and have the largest effective area with 
a given perimeter of any known figure. Pipes should be made 
in lengths convenient for handling, say 8 or 10 ft., having joints 
lapped nearly 2 inches in direction of the air current. Joints 
should be riveted about every 4 inches, to hold them securely 
together and prevent sagging of the pipe between supports, 
and to insure their being tight they should be soldered all the 
way around. Section ends should be placed over supports and 
laps of from 3 to 4 inches made at each joint and also soldered. 
The end of the main pipe, when not connected direct with an 
air-chamber on the cupola, should be divided into two or more 
branches of equal capacity for connection with the tuyeres or 
air belt, and rounded curves or elbows used in changing the 
direction of pipes, A pipe should never terminate abruptly, 
and branches should not be taken out of the side for supplying 
the cupola, as is frequently done. The area of main pipes and 
also branch pipes should be increased as the distance from the 
blower to the cupola is increased ; and as a guide for increasing 
their diameter in proportion to the length of pipe, we do not 
think we can do better than give our readers the excellent table 
prepared by the Bufifalo Forge Co., Buffalo, N. Y,, as follows: 



396 



THE CUPOLA FURNACE. 



■S.S--0 

.2 "^r O 

Q °-9 

•— * in 



«\fN?l\CO\eO\50\M\05\CO\CO\Tjl 



, ,, ... ,- .„ ^ -^. -,- ,„ ^- .., ,., ^^\5f \Tii\co\<»\oo\»i; .S 

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BLAST PIPES AND BLAST. 397 

DIAMETER OF BLAST PIPES. 

It will be seen, by reference to the following table, that the 
diameter of pipe for transmitting or carrying air from one 
point to another, changes with the length or distance which the 
air is carried from the blower to the furnace, or other point of 
delivery. 

As air moves through pipes, a portion of its force is retarded 
by the friction of its particles along the sides of the pipe, and 
the loss of pressure from this source increases directly as the 
length of the pipe, and as the square of the velocity of the 
moving air. 

This fact has long been known, and many experimenters 
and engineers, by close observation and long-continued experi- 
ments, have established formulas by which the loss of pressure 
and the additional amount of power required to force air or 
gases through pipes of any length and diameter may be 
computed. 

As these formulas are commonly expressed in algebraic 
notation, not in general use, we have thought it desirable to 
arrange a table showing at a glance all the necessary propor- 
tionate increase in diameter and length of blast pipes and 
conical mouth-pieces, in keeping up the pressure to the point 
of delivery. It is often the case, where a blower is cofidemned 
as being insufficient, the cause of its failure is that the pipe 
connections are too small for their lengths, coupled with a 
large number of short bends, without regard to making the pipe 
tight, which is a necessity. 

The table, diameter of pipes, given on the following page, 
showing the necessary increase in the size of pipes in proportion 
to the lengths, is what we call a practical one, and experience 
has proved the necessity for it. 

The connection of blast pipes with cupola.s is also a matter 
to which entirely too little attention is given, and is frequently 
the cause of poor melting when cupola is otherwise properly 
constructed. As stated elsewhere, tuyeres should be large 
enough to admit blast to a cupola freely, and to obtain good 



398 



THE CUPOLA FURNACE. 



results in melting it must be fully and evenly distributed to 
the tuyeres. When blast is delivered direct to tuyeres through 
branch pipes, the branches should be taken off the main pipe 
in as near a direct line with the current of the blast in the 
main pipe as possible, and its course to the tuyeres should be 
changed by long curves or round elbows in the pipes, to pre- 
vent the velocity of the air being checked and blast thrown 
back in the pipe. The combined area of all the branch pipes 
should be equal to the area of the main pipe, and not less as is 
frequently the case, owing to a mistake being made through 
the erroneous idea that a multiple of the diameter of two or 
more small pipes is equal to the area of one large one of their 
combined diameters. If this were the case two five-inch pipes 
would have an area equal to one ten-inch pipe, which is not so, 
as will be seen by the table on p. 396, which may be of value 
to foundrymen in arranging their blast pipes. 



DIAMETER AND AREA OF PIPES. 



Diameter. 


Area. 


Diameter. 


Area. 


Diameter. 


Area. 


2 


3-141 


8M 


53-456 


IA% 


165.13 


2M 


3-967 


8i„ 


56-745 


14% 


170.85 


2)2^ 


4908 


8^ 


60.132 


15 


176.71 


2^ 


5-939 


9 


63.617 


^sH 


182.65 


3 


7.068 


9K 


67.200 


^^'i 


188.69 


3H 


8.295 


9% 


70.882 


15% 


194.82 


3% 


9.621 


9% 


74.662 


16 


201.06 


3K 


1 1 .044 


10 


78.539 


16)^ 


207.39 


4 


12.566 


1034 


82.516 


161^ 


213.82 


4)4 


14.186 


103^ 


86 590 


16% 


220.35 


4li 


15-904 


IC^ 


90.762 


^7, 


226.98 


A% 


17.720 


II 


9S-033 


17M 


233-70 


5 


19-635 


")i 


99402 


^iVz 


240.52 


5K 


21.647 


1 1 % 


105.86 


17% 


247-45 


5,^-2 


23-758 


"^ 


10843 


18 


2S4-46 


5^ 


25.967 


12 


113.09 


i8>i 


261.58 


6 


28274 


12K 


117.85 


i^li 


268.80 


6K 


30.679 


1 21^^ 


122.71 


1 '8% 


276,11 


6>^ 


33-183 


12% 


127.67 


19 


283-52 


6% 


35-784 


13 


132-73 


19% 


291.03 


7 


38-484 


I3M 


137-88 


19 H 


298.64 


IV^ 


41.282 


13^2^ 


143- 1? 


i 19% 


306.35 


7>2 


44.178 


13% 


148.48 


20 


314.16 


IYa 


47-173 


14 


15393 






8 


50.265 


I4>i 


159.48 







BLAST PIPES AND BLAST. 399 

In connecting blast pipes direct with tuyeres, either by long 
branch pipes from the main pipe or short ones from a belt air 
chamber not attached to cupola shell, care should be taken to 
have as few joints or connections in the pipes as possible, and 
every joint should be made in such a way that the jar made in 
chipping out andcharging the cupola will not cause the joints 
to leak after they have been in use a short time. In leading 
pipes out of an air chamber they cannot always be placed in 
line with the current of the blast, and must be filled from pres- 
sure of blast in the air chamber, but the connecting pipes may 
be shaped to guide the blast smoothly from the air chamber to 
its destination. 

In Fig. 83 is shown as perfect a connection of air chambers 
of this kind as can be made. In this illustration the belt pipe 
A A is placed up out of the way and of danger of being injured 
when making up or working the cupola, and the branch pipes 
to each tuyere are straight and smooth inside and the pipe is 
given a curve at the bottom to throw the blast into the tuyere 
without having the force of its current impaired, and the tuyeres 
are of a size to admit the full volume of blast from the pipe. 
Only two joints are required in connecting the air chamber with 
the cupola, and these are made in such a way that they may be 
securely bolted or riveted, and all leakage prevented. 

In contrast with the neat arrangement of pipes on this cupola 
is shown the other extreme of poor arrangement in illustration 
Figure 85. This is a section of a " perfect cupola" illustrated 
and described in T/ic Iron Age some years ago, and while other 
parts of the cupola may have been perfect, this part was cer- 
tainly very imperfect. The air chamber and its connecting 
pipes are made of cast iron. The connecting pipes are cast in 
three pieces, necessitating the making of four joints. The air 
box is cast in two pieces, requiring another joint; and a peep- 
hole and an opening for escape of slag and iron running into 
the tuyeres, is placed in the pipe, making in all seven joints and 
openings in each connection to be made and kept air-tight. 
The jar in working the cupola, together with the small explo- 



400 THE CUPOLA FURNACE, 

sions of gas that frequently take place in cupolas and pipes^ 

Fig. 85. 




POOR ARRANGEMENT OF BLAST PIPES. 

would naturally tend to loosen many of these joints, and a large 



BLAST PIPES AND BLAST. 4OI 

amount of blast would be lost through leakage of joints. The 
many joints make more or less roughness in the pipes, thus im- 
peding the blast. The turn in the pipe for connection with the 
tuyere is square and the course of the current of air is abruptly 
changed, and the tuyere is entirely too small to admit the full 
volume of blast from the pipe to the cupola, and only by a 
heavy pressure of blast could the air be forced into the cupola 
in sufficient quantities to do good melting. 

In Fig. 83 is shown another way of connecting a belt air- 
chamber with the tuyeres. In this case the pipe is made of 
galvanized iron, and the tuyere boxes are made of cast-iron and 
are large, giving abundant room for changing the direction of 
the blast current. Only two joints are made in connecting the 
air-chamber with the cupola ; beside these joints, the end of the 
tuyere box is closed with a large door, the full size of the box, 
and a peep-hole is placed in the door, making two more open- 
ings to be kept air-tight. Many cupolas are in use having their 
blast connections arranged in this way, and while the arrange- 
ment is good, it is not perfect, and a great deal of blast is 
lost through leakage of joints — the principal loss occurring 
around the large door and at the joint connecting the galvan- 
ized iron pipe with the cast-iron tuyere box. 

The very best way of connecting blast pipes with cupola 
tuyeres is by means of a belt air-chamber riveted to the cupola 
casting, as shown in Figs. 28, 30 and 31, or by an inside air- 
chamber, as shown in Figs, "jz and "j^. In either case the air- 
chamber is riveted to the cupola shell and the joint made per- 
fectly air-tight, and in case of jar to the cupola, the air-chamber 
being part of the cupola, oscillates with it, and the jar in chip- 
ping out and charging does not loosen the joint and cause leak- 
age of blast. The blast pipes may also be securely riveted or 
bolted to the air-chamber and a perfectly tight joint made. In 
constructing cupolas in this way, care should be taken to make 
the air-chamber of a sufficient size to admit of a free circulation 
of blast and supply all the tuyeres with an adequate amount for 
good melting. When the air chamber is small, the blast-pipe 
26 



402 



THE CUPOLA FURNACE. 



should be connected with it on each side of the cupola, and 
on the side or top as found most convenient. When the 
chamber is large and there is an abundance of room for the 
escape of blast from the pipe, one pipe is sufificient and it 
may be connected on the side or top. When attached on the 
side it should be placed in line with the circle of the cupola as 
shown in Fig. 34, to cause the current of blast to circulate 
around the cupola and facilitate its escape from the pipe. When 

Fig. 86. 




BLOWER PLACED NEAR CUPOLA. 



the current of blast is thrown directly against the cupola casing 
or bottom of the chamber in a narrow air-chamber, the mouth 
of the pipe should be enlarged, to facilitate the escape of blast 
into the chamber ; for cupolas of this construction may be made 
a complete failure by failing to provide a sufficient space at the 
end of the pipe for escape of blast into the air-chamber, when 
the chamber is of a sufificient size to supply the cupola. Con- 
nections with the inner air-chambers of limited capacity should 



BLAST PIPES AND BLAST. 403 

be made on each side by means of an air or tuyere box placed 
outside, as shown in Fig. 6, and the pipe connected on top to 
equaHze the volume of blast supplied to each tuyere. 

Long blast pipes often cause poor melting, from the volume 
of blast delivered to a cupola being reduced by friction in the 
pipes, and in all cases the blower should be placed as near the 
cupola as possible, in Fig. 86 is shown a very neat arrange- 
ment in placing a blower near a cupola and at the same time 
having it up out of the way of removing molten iron or the 
dump from the cupola, and the space under it may be utilized 
for storing ladles, etc. In this illustration is also shown a very 
perfect manner of connecting the main pipe with an air cham- 
ber. The pipe is divided into two branches of equal size in 
line with the current of blast from the blower, and connected 
with the air chamber on each side by curved pipes arranged 
in such a way as not to check the current of air as it passes 
through the pipe. 

PLACING A BLOWER. 

A blower should always be placed at as near a point to a 
cupola as is consistent with the arrangement of the foundry- 
plant, and it should be l.iid upon a good, solid foundation, and 
securely bolted to prevent jarring, as there is nothing that 
wrecks a blower so quickly as a continual jar when running at 
high speed. In Fig. 86 is shown a convenient way of placing a 
blower near a cupola, and at the same time having it out of the 
way. But when so placed, the blower should be laid upon a 
solid frame-work of heavy timber, and securely bolted down to 
prevent jarring when running. It should also be boxed in to 
prevent air being drawn in from the foundry, and have an open- 
ing provided for supplying air from the outside, for air drawn 
from a foundry when casting and shaking-out are taking place 
is filled with dust and steam, which are very injurious to a 
blower and pipes. 

A blower should never for the same reason be placed in a 
cupola-room or a scratch room in which castings are cleaned ; 



404 THE CUPOLA FURNACE. 

for it is impossible to exclude dust from the bearings when so 
placed, and when a bearing once begins to cut, it makes room 
for a greater amount of dust, and cuts out very rapidly in blow- 
ers run at high speed. Dust and steam also corrode and de- 
stroy blast wheels which are inside the blower and out of sight, 
and a blast wheel may be almost entirely destroyed and not 
discovered until it is found the cupola is receiving no blast. To 
prevent a blower from being destroyed in this way, and insure 
a proper volume of blast for a cupola, the blower should be 
placed in a clean, dry room and supplied with pure air from 
the outside. If it cannot be so placed near a cupola, it had 
better be placed at some distance, in which case the blast-pipe 
must be enlarged in proportion to its length, as described else- 
where. When a blower is placed in a closed room, windows 
should be opened to adrnit air when it is running, and when 
the air about the room is filled with dust, a pipe or box for 
supplying pure air should be run off to some distance from the 
blower and the room kept tightly closed. 

BLAST GATES. 

These devices are especially designed lor opening and clos- 
ing blast pipes, such as are employed for conveying air be- 
tween blowers and cupolas. There are several different de- 
signs of blast gate?, but the one shown in Fig. 87 is the one 
most commonly used by foundrymen. They aie manufactured 
and kept in stock by all the leading manufacturers of blowers, 
and cost from one dollar upwards, according to size of blast 
pipe. 

The employment of the blast gate places the volume of 
blast delivered to a cupola under control of the melt-er, which 
feature is frequently very important in the management of 
cupolas in melting iron for special work, or in case of accident 
or delay in pouring. In foundries in which the facilities for 
handling molten metal are limited and melting must at times 
be retarded, to facilitate its removal from the cupola as fast as 
melted, and in foundries where the amount of iron required to 



BLAST PIPES AND BLAST. 



405 



be melted per hour is limited by the number of molds or chills 
employed, from which castings are removed and the molds re- 
filled, it is very important that the blast should be under con- 
trol of the melter. In such foundries the cupolas are general!}' 
of small diameter and frequently kept in blast for a number of 
hours at a time, and it is often desired to increase the volume 
of blast to liven up the iron, and decrease it to reduce the 
amount melted in a given time. 

The blast gate places the blast under control of the melter 
and enables him to increase or diminish its volume as deemed 

Fig. 87. 




BLAST GATE. 



necessary to obtain the best results in melting. They are often 
of value in regular cupola practice to reduce the volume of 
blast and retard melting for a few minutes while pouring a 
large piece of work, in foundries where the facilities for hand- 
ling large quantities of molten iron are limited, and the speed 
of blower cannot be reduced without reducing the speed of 
machinery in other parts of the works or stopping the blower 
entirely, which is not good practice after a cupola has been in 
blast for some time. 



406 THE CUPOLA FURNACE. 

The gate is also a safeguard against gas explosions, which 
often occur from the accumulation of gas in pipes during the 
temporary stoppage of the blower. The gate should always 
be placed in the pipe near the cupola, and closed before stop- 
ping the blower and not opened until it is again started up. 

EXPLOSIONS IN BLAST PIPES. 

Violent explosions frequently take place in cupola blast pipes,, 
tearing them asunder from end to end. These explosions are 
due to the escape of gas from the cupola into the pipes during 
a temporary stoppage of the blower in the course of a heat. 
The explosion is caused by the gas being ignited when the pipe 
becomes over-charged, or the instant the blower is started and 
the gas is forced back into the cupola. Such explosions gen- 
erally take place in pipes placed high or arranged in such a 
way as to have a draught toward the blower. But they may 
occur in any pipe if the cupola is well filled when a stoppage 
takes place and the blower is stopped for a great length of 
time. 

Such explosions may be prevented by closing the blast-gate 
if placed near the cupola, or by opening the tuyere doors in 
front of each tuyere and admitting air freely to the pipe. Such 
precaution should always be taken the instant the blast is 
stopped, as a pipe may be exploded after only a few minutes' 
stoppage of the blower, and men may be injured or the blower 
destroyed by the explosion. 

BLAST GAUGES. 

A number of air or blast gauges have been designed and 
placed upon the market for determining the pressure of blast 
in cupola blast pipes and air-chambers. These gauges are of a 
variety of design, and are known as steel spring, water and 
mercury gauges. They are connected with a blast pipe or air- 
chamber by means of a short piece of gas-pipe or a piece of 
small rubber hose, through which the air is admitted to the 
gauge. The pressure of blast is indicated by a face dial and 



BLAST PIPES AND BLAST. 407 

hand on the spring gauge, and by the graduated glass tube of 
the water and mercury gauges, pressure being shown up to two 
pounds, in fractions of an ounce. These gauges, when in good 
order, indicate very accurately the pressure of blast on a cu- 
pola, and when tuyeres and pipes are properly arranged, show 
to some extent the resistance offered to the free escape of blast 
from the pipe and the condition of the cupola in melting. But 
they do not indicate the number of cubic feet of air that pass 
into a cupola in any given length of time, and a gauge may 
show a pressure of six or eight ounces when scarcely a cubic 
foot of air is passing into a cupola per minute. 

With a pressure blower these gauges show a gradual increase 
of pressure in the pipe when a cupola is clogging up, and may 
enable a foundryman to prevent bursting of the pipe ; but with a 
non-positive blower they show nothing that is of any value to 
a foundryman in melting, so far as we have been able to learn. 
The volume of blast is what does the work in a cupola, and not 
the pressure ; and a high pressure of blast does not always indi- 
cate a large volume of blast, but rather the reverse, for little if 
any pressure can be shown on a gauge when blast escapes 
freely from a pipe. 

We have seen two cupolas of the same diameter, one melting 
with a two-ounce pressure of blast and the other with a six- 
ounce pressure, and the cupola with the low pressure doing the 
best melting. This was simply because with the low pressure 
the air was escaping from the pipe into the cupola and with 
the high pressure it was not, and the high pressure was wholly 
due to the smallness of the tuyeres which prevented the free 
escape of blast from the pipe mto the cupola. 

A definite number of cubic feet of air has been determined by 
accurate experiments to be required to melt a ton of iron in a 
cupola, and an air-gauge to be of any value in melting must in- 
dicate the number of cubic feet of air that actually enter a 
cupola at the tuyeres. We have at the present time no such 
gauge, and in the absence of such a gauge the foundryman's 
best guide as to the number of cubic feet of air supplied to his 



40S THE CUPOLA FURNACE. 

cupola is the tables furnished by all manufacturers of standard 
blowers, giving the number of revolutions at which their 
blowers should be run, and the number of cubic feet of air de- 
livered at each revolution. From these tables a foundryman 
may figure out the exact number of cubic feet of air his cupola 
receives, provided there is no leakage of air from pipes or 
tuyeres and the tuyeres are of a size that will permit the air to 
enter the cupola freely. 

BLAST IN MELTING. , 

A cupola furnace requires a large volume of air to produce 
a thorough and rapid combustion of fuel in the melting of iron 
or other metals in the furnace. Numerous means have been 
devised for supplying the required amount of air, among them 
the draught of a high chimney or stack, and the creating of a 
vacuum in the cupola by means of a steam jet, placed in a con- 
tracted outlet of a cupola as shown in Figs, tg and 70. These 
means of supplying air are a success in cupolas of small diam- 
eter and limited height, but even in these cupolas the volume 
of air that can be drawn in is not sufficient to produce rapid 
melting, and it is doubtful if iron could be melted at all in a 
cupola of large diameter and of a proper height to do econom- 
ical melting, by either of these means of supplying air. Owing 
to the peculiar construction of a cupola furnace and the manner 
of melting, the free passage of air through it is restricted by the 
iron and fuel required ; and rapid melting can only be done 
when air for the combustion of the fuel is supplied in a large 
volume, which can only be by a forced blast. 

A number of machines have been devised for supplying this 
blast, among the earliest of which were the leather bellows, 
trompe or water blast, chain blast, cogniardelle or water-cylin- 
der blast, cylinder or piston blower. These have, as a rule, 
given away to the more modern fan blower and rotary positive 
blast blower, a number of which will be described later on. 

The relative merits of a positive and non-positive blast, is a 
very much disputed question. It is claimed by many that 



BLAST PIPES AND BLAST. 409 

with a positive blast a definite amount of air is supplied to 
a cupola per minute or per hour, while with a non-positive 
blower or fan there is no certainty as to the amount of air the 
cupola will receive. This is very true, for a cupola certainly 
does not receive the same amount of air from a fan blower when 
the tuyeres and cupola are beginning to clog as it does from a 
positive blower when there is no slipping of the belts. But is 
it advisable to supply a cupola with as large a volume of blast 
when in this condition as when working open and free? Does 
not the large volume of blast have a chilling effect upon the 
semi-fluid mass of cinder and slag, and tend to promote clog- 
ging about the tuyeres while keeping it open above the tuyeres ; 
while blast from a non-positive blower would percolate through 
small openings in the mass, and be more effective than a large 
volume of blast from a positive blower forming large openings 
in it through which it escaped into the cupola? 

These are questions we have frequently tried to solve b)' 
actual test; but it is so difftcult to find two cupolas of the same 
dimensions melting the same sized heats for the same class of 
woik, one with a positive and the other with a non-positive 
blast, that we have never been able to test the matter. We have 
melted iron with nearly all the blowers now in use and with a 
number of the old-style ones, and think there is more in the 
management of a cupola than there is in a positive or non- 
positive blast. Good melting maybe done with either of them, 
when the cupola is properly managed, and it cannot be done 
wiih either of them when the cupola is not properly managed. 
Until the management of cupolas in every-day practice is re- 
duced to more of a system than at present, it will be impossible 
to determine any practical advantage in favor of either blower 
over the other. So far as we are concerned, we have no prefer- 
ence in blowers, but make it a rule to charge a cupola more 
openly when melting with a non-positive blast, for the reason 
that stock may be packed so closely in a high cupola that the 
volume of blast that is permitted to enter at the tuyeres may 
not be reduced by preventing its escape through the stock. 



4IO THE CUPOLA FURNACE. 

The amount of air that is required for combustion of the fuel 
in melting a ton of iron has been determined by accurate ex- 
periments to be about 30,000 cubic feet, in a properly con- 
structed cupola in which the air was all utilized in combustion 
of the fuel. This amount of air if reduced to a solid would 
weigh about 24,000 lbs., or more than the combined weight of 
the iron and fuel required to melt it. In a cupola melting ten 
tons per hour, 300,000 cubic feet of air must be delivered to the 
cupola per hour to do the work. It will thus be seen, that a 
very large volume of blast is required in the melting of 10 tons 
of iron. To deliver this amount of air to a cupola from a 
blower that is capable of producing it in the shape of a blast, 
the blast pipes must be arranged in such a way that the velocity 
of the air is not impeded by the pipes; and the tuyeres must 
be of a size to admit the air freely to the cupola. This is not 
always the case, for we have seen many cupolas in which the 
combined tuyere area was not more than one-half that of the 
blower outlet. The object in making the tuyere area so small 
was to put the air into the cupola with a force that would drive 
it to the center of the stock. This was the theory of melting in 
the old cupolas with small tu)"eres, but this was wrong, for air 
cannot be driven through fuel in front of a tuyere, as an iron 
bar could be forced through it, even with a positive blast; and 
when the air strikes the fuel it cannot pass through it, but 
escapes through the crevices between the pieces of fuel. These 
crevices may change its direction entirely, and the same force 
that drives it into the cupula impels it in the direction taken,, 
which will be the readiest means of escape, and is more liable 
to be up along the lining than toward the center of the cupola. 
For, as a rule, stock does not pack so close near the lining as 
toward the center, and the means taken to prevent the escape 
of blast around the lining is the very thing that causes it to 
escape in that way. Since blast cannot be driven through fuel 
to the center of a cupola and can only escape from the tuyeres 
through the crevices between the pieces of fuel, the only way to 
force it to the center of a cupola is to supply a sufficient volume 



BLAST PIPES AND BLAST. 411 

of blast to fill all of the crevices between the pieces of fuel. 
This can only be done by discarding the small tuyeres and 
using a tuyere that will admit blast freely to a cupola. 

In placing tuyeres in a cupola, it must be remembered that 
the outlet area of a tuyere is governed by the number of crev- 
ices between the pieces of fuel in front of the tuyere through 
which the blast may escape through the tuyere. With small 
tuyeres a large piece of fuel may settle in front of the tuyere 
in such a way that its outlet is not equal to one one-hun- 
dreth part of the tuyere area, in which case the tuyere is ren- 
dered useless, and may remain useless throughout the heat. 
P'or these reasons small tuyeres should never be placed in a 
cupola. For small cupolas we should recommend the trian- 
gular tuyere, Fig. 14, for the reason that it tends to prevent 
bridging, and its shape is such that it is less liable to be closed 
by a large piece of fuel than a round tuyere of equal area. 
The vertical slot tuyeres, Figs. 10 and 1 1, are also for the same 
reason good tuyeres for small cupolas. , 

For large cupolas we think the expanding tuyere, Fig. 3, is 
the best, and if we were constructing a large cupola we should 
use this tuyere in preference to any other, and make the outlet 
at least double the size of the inlet, and should place the tujeres 
so close together that the outlets would not be more than six 
or eight inches apart. This would practically give a sheet 
blast, and distribute air evenly to the stock all around the 
cupola. The width of the tuyere can be made to correspond 
with the diameter of cupola, and may be from three to six 
inches, and should be of a size that will permit blast freely to 
enter the cupola. Parties who have been melting with small 
tuyeres and put in large ones upon this plan must change 
their bed and charges to suit the tuyeres, for this arrangement 
of tuyeres would probably be a complete failure in a cupola 
charged in the same way as when not more than one-fourth of 
the blast supplied by the blower entered the cupola. 

The largest cupolas in which air can be forced to the center 
from side tuyeres with good results would appear from actual 



412 THE CUPOLA FURNACE. 

test to be from four and a half to five feet. Larger cupolas 
than this have been constructed, and are now in use, but they 
do not melt so rapidly in proportion to their size as those of a 
smaller diameter. To illustrate this, we might cite the Jumbo 
Cupola of Abendroth Bros., Port Chester, N. Y., already de- 
scribed, in which the diameter at the tuyeres is 54 inches, and 
above the bosh 72 inches, in which 15 tons of iron have been 
melted per hour for stove-plate and other light castings. 

The Carnegie Steel Works, Homestead, Pa., have cupolas of 
seven and one-half feet diameter at the tuyeres and ten feet 
diameter above the bosh, in which the best melting per hour is 
only fourteen tons. The area of this cupola at the tuyeres is 
almost three times that of Abendroth's cupola, yet the amount 
of iron melted per hour is actually less than that of the smaller 
cupola. Tuyeres have been arranged in different ways in this 
large cupola, and from one to four rows used, yet the melting 
was not in proportion to the size of cupola. This would seem 
to indicate that the cupola was not properly supplied with blast 
near the center, and the melting done in the center was caused 
principally by the heat around it; which is probably the case, 
for the cupola is kept in blast night and day, for six days, and 
melting must take place in the center, or the cupola would 
chill up. 

There are many cupolas of sixty inches diameter at the 
tuyeres in use in which good melting is done, but this would 
seem to be the limit at which good melting takes place in a 
cupola supplied with blast from side tuyeres, for above this 
diameter the rapidity of melting does not increase in proportion 
to the increase in size of cupola. 

There has been considerable experimenting done during the 
past two or three years with a center blast tuyere for admitting 
blast to the center of a cupola through the bottom. We have 
had no practical experience with this kind of tuyere for the last 
twenty-five years, when we placed one in a small cupola with 
side tuyeres and found no advantage in it; probably for the 
reason that a sufificient quantity of air for an even combustion 



BLAST PIPES AND BLAST. 413 

of the fuel was supplied to the center of the cupola from the 
side tuyeres. 

During the past few years, we have visited a number of foun- 
dries in which the center blast was being tried, but in every 
case the tuyere was out of order or not in use at the time of 
our visit. The great objection to this tuyere seems to be its 
liability to be filled with iron or slag and rendered useless. 
Should this objectionable feature be overcome, it would cer- 
tainly be a decided advantage in melting in cupolas of large 
diameter in connection with side tuyeres. In cupolas of small 
diameter with side tuyeres, we do not think a center blast 
would increase the melting capacity of a cupola, for the reason 
that air can be forced to the center of a small cupola from side 
tuyeres, when properly arranged and of a proper size. 

With a center blast alone, it is claimed that considerable sav- 
ing is effected in lining and fuel. It is reasonable to suppose 
that a saving in lining might be effected by a center blast; for 
the most intense heat that is created by the blast is transferred 
from near the lining to the center of the cupola, and the tend- 
ency to bridge is greatly reduced. As to the saving of fuel, 
there never was a new tuyere that did not " save fuel," and 
there have been hundreds of them, but consumption of cupola- 
fuel is still too large. 



CHAPTER XXV. 



BLOWERS. 



To describe and illustrate all the blowing apparatus designed 
for furnishing blast for cupolas would require a larger volume 
than this one is designed to be, and would be of little practical 
value, as founders are not looking for obsolete but up-to-date 
machinery. We shall therefore confine ourselves to a descrip- 
tion of a few and most improved blowers. 

The blowers used for this purpose at the present time are 
confined almost exclusively to two types, viz.. Rotary Pressure 
Blowers and Fail Blowers. Each of these types has its advo- 
cates, and both are extensively used in supplying cupola blast. 
That they may be employed for this purpose is clearly demon- 
strated by the many hundreds of each type now in use. 

The question of superiority of one type over the other for 
furnishing cupola blast is one that has been extensively dis- 
cussed, and for which extravagant claims have been made by 
the manufacturers of each, and proved by them to their own 
satisfaction and in many cases to the satisfaction of their 
patrons ; and where such claims can be proved by the manu- 
facturers of each type, there must be some good points in each. 

We have melted iron in all the various styles of cupolas now 
in use, and in many of the old styles that have gone out of use 
with both these types of blowers, and have also seen a good 
deal of melting done with them, and are of the opinion that as 
fast and economical melting can be done with one type as with 
the other, when a cupola is properly managed ; and good 
melting cannot be done with either one of them if a cupola is 
not properly managed. It is just as well to have the blast 
shut ofT by the settling of stack and clogging of the cupola, as 
is claimed to occur with a fan blower, as it is to force blast 

(414) 



BLOWERS. 415 

into a cupola when in this condition, as can be done with a 
pressure blower. For in such cases, the blower if of a proper 
size is not responsible for this condition of the cupola, and 
when in this condition good melting cannot be done with either 
blower. The selection of a blower is therefore a matter to be 
decided by each founder, and the points to be considered are, 
which is the most economical blower under the conditions in 
which it is to be placed. 

THE GRKEN PATENTED POSniVE FRPSSURE BLOWER. 

This is a blower of a new design recently placed upon the 
market by the Wilbraham-Baker Blower Co., to take the place 
of the Baker blower, for many years manufactured by them. 
The new blower is said to be a great impro\ement upon the 
Baker blower, which for many ) ears was one of the best in use 
for foundry cupoLis. 

We regret that the descriptive matter of the Green Blower 
was not ready in time for this work, and we are unable to give 
a detailed description of its construction and advantages for 
cupola work. 

CONNFRSVILLE CYCLOmAL BLOWER. 

The Connersville Positive Pressure Blower is one of the latest 
designs of blower, and has only been manufactured for a few 
years. A description of it is taken from the excellent circular, 
which is well worth reading by those contemplating the pur- 
chase of pressure blowers, and is as follows: 

The cycloidal curves, their nature, peculiarities and possi- 
bilities, have always b( en an attractive study, not only to the 
theoretically inclined, but more particularly to those interested 
in the many important applications of these curves in practical 
mechanics. The especial value of combining the epi- and 
hypocycloids to form the contact sui faces of impellers for rotary 
blowers, gas exhausters and pumps has long been recognized, 
and many attempts have been made to utilize them in that con- 
nection, but in vain. While conceded to give the theoretically 
correct form to a revolver or impeller, it came to be regarded 



41 6 THE CUPOLA FURNACE. 

as impossible to produce such surfaces by machinery with suffi- 
cient accuracy to admit of their use in practice with anj' degree 
of satisfaction. It remained for us to demonstrate that it could 
be done, and in a highly successful manner as well. 

Fig. 88 is an illustration showing a cross section of our new 
cycloidal blower, and particularly of the revolvers or impellers, 
their form, relation to each other, and to the surrounding case. 
A glance only is required to discern the superiority of this 
method of construction over all others. 

The vital part of every machine of this class is the impeller, 

Fig. 88. 




SECTIONAL VIEW OF CONNERSVILLE CYLLOIDAL BLOWER. 

as on it depends economy of operation and efficiency in results. 
That we have the ideal form for an operating part is self-evident. 
It will be noted that there are two impellers only, and each is 
planed on cycloidal lines with mathematical accuracy. Now, it 
is one of the well-known peculiarities of the epicycloidal and 
hypo-cycloidal curves, when workeil together as in our machines, 
that there is a constantly progressive point of contact between 
the impellers. As a result of this regular advance of the point 
of contact, the air is driven steadily forward, producing a 
smooth discharge that is conducive to the highest economy. 

The advantage of this arrangement over the use of arcs of 
circles to approximate contact curves is very great, as it is a 



BLOWERS. ' 417 

well-demonstrated fact that circular arcs whose centers are not 
coincident with the centers of revolution can not keep practical 
contact through an angle of more than four or five degrees. On 
the contrary, the contact does not progress continuously, but 
jumps from one point to another across intervening recesses as 
the impellers revolve, leaving pockets in which the air is alter- 
nately compressed and expanded, producing undesirable pulsa- 
tions in the blast, a waste of power, and necessitating two points 
of contact at one time in four positions in each revolution. 

Another advantage of the cycloidal form is that, at the point 
of contact, a convex surface is always opposed to a concave 
surface; that is, the epi-cycloidal part of one impeller works 
with the hypo- cycloidal part of the opposite impeller. The 
consequence of this is to produce a long contact or distance 
through which the driven air must travel to get back between 
the impellers, instead of the short contact that results when 
two convex surfaces oppose each other, as is the case in other 
machines of this character. 

Attention has previously been directed to the fact that the 
point of contact between the impellers continuously progresses ; 
indeed, the path it describes is a circle. One result of this con- 
tinuously-progressive contact, as before mentioned, is a smooth, 
reliable blast. Another is, as has also been noted, the absence 
of any pockets or cavities in which air can be gathered, com- 
pressed and then discharged back toward the inlet side of the 
machine, thereby entailing a waste of power and shortening the 
life of the blower by subjecting the impellers, shaft and gears to 
a needless shock, strain and wear. Furthermore, the impellers 
can be in contact only at one point at the same instant — in no 
position is it possible for them to touch each other at two points 
at once ; hence, there are no shoulders to knock together when 
the speed is more than nominal. 

On account, also, of there being no popping due to the ex- 
pansion of air when released from the pockets in which it has 
been caught and compressed, and no pounding of the impellers 
together, that disagreeable din and vibration usually associated 
27 



41 8 ' THE CUPOLA FURNACE. 

with machines of this class is eHminated, and our blowers run 
with practically no noise. This is a feature that will commend 
itself to parties having had experience with other pressure 
blowers. 

Another point contributing to the evenness and uniformity of 
the di>charge is the fact that the extremities of the impellers 
are curved. Thus, as they sweep past the outlet, there is a 
gradual equalization of the pressure instead of a sudden shock, 
such as results from the passage of two sharp edges, which 
shocks are sodi^trimental to all working parts, as has been noted. 

From what has been stated, we scarcely need to add that the 
machme is positive in iis action. All the air that enters the 
blower is inclosed by the impellers, forced forward and dis- 
charged through the outlet pipe. The leakage is insignificant, 
and there is no compressed air allowed to escape backward. 
Hence, all the power applied to the machine is used for the 
purpose intended — the maintenance of an even blast — and none 
of it is wasted on needless work. 

Furthermore, as the contact between the impellers and the 
surrounding case is perfect at all limes, the amount of pressure 
that can be developed and sustained depends solely on the 
strength of the machine and the power applied. 

Each of the two impellers is cast in one piece and well ribbed 
on the inside to prevent changes in form under varying condi- 
tions. It is part of our shop practice to press the shaft into the 
impeller with a hydrostatic press, finish the journals to standard 
size, mount the impeller on a planer and plane its entire surface 
accurately. By this means we secure perfect symmetry and ex- 
actness with respect to the journal on which it revolves, and, as 
a consequence, can produce a machine that will run more 
smoothly, and in either direction, at a higher speed and press- 
ure than it has been possible to attain heretofore. 

It will be observed that the C}'cloidal curves produce an im- 
peller with a broad waist. We have availed ourselves of this 
to use a high grade steel shaft of about twice the sectional area 
of those foinid in competing machines. The advantages of this 
need not be enumerated. 



BLOWERS. 



419 



In Fig. 89 we illustrate the style of blowers that are most 
largely sold, i. e., those pulley driven. It will be noticed that 
we use one pulley only. We can, however, when desired, put 
a pulley on each end, but because of the large shafts, wide-faced 
gears, and the fact that there is a bearing the entire distance from 




HORIZONTAL BLOWER. 



the gears to the impellers, it is seldom necessary. In any event, 
we do not recommend two belts very highly, as, owing to the 
difference in the amount of stretch in the leather, it is usually 
the case that one transmits most of the power. Indeed, it 
sometimes occurs that they work against each other. 



NUMBERS, CAPACITIES, ETC., OF THE CYCLOIDAL BLOWERS. 



Number of Blower 

•Capacity in cubic feet per rev- 

oluiion 

Ordinary speed 

Diameter of pipe opening .... 



400 350 

4 6 



3 
300 



5^ 8i2i^24>^ 42 07 100 
27s 250 200 175 150 125 100 

10! 121 14 16, 20 24 30 



By " ordinary speed " we mean what would be about an 
average of every-day duty. It must be understood, however, 
that the peculiar form of the impellers of our blowers, in con- 
nection with the other superior points in construction to which 
we have called attention, permits of higher speeds than com- 
peting machines. 



420 



THE CUPOLA FURNACE. 



The speed at which positive pressure blowers are run may 
be classed as "slow"; therefore power can be taken direct 
from the main line of shafting or from a countershaft driven at 
the same rate. 

Fig. 90 shows a blower with an engine to furnish the required 
power, both on the same bed-plate. By such a combination all 
shafting, pulleys, gears and belts are dispensed with, as the 
crank-shaft of the engine is coupled direct to a shaft of the 

Fig. 90. 




VERTICAL BLOWER AND ENGINE ON SAME BED-PLATE. 

blower, thereby efifecting a very simple but most efificient driv- 
ing- arrangement. We recommend the installation of such a 
plant when the blower is to be located at a considerable distance 
from the line shaft, as it will be found more economical to pipe 
steam to the engine than to transmit power by shafting or cable. 
But even where power is convenient there are many good 
reasons why it will be found much more desirable to operate 
the blower with its own engine. For instance, it can be run 
independent of the other machiner>', as necessity or conven- 



BLOWERS. 



421 



ience may often require, and also permits the speed of the 
blower to be varied as there is a demand for an increased or 
diminished amount of blast, while otherwise this could not be 
accomplished without a change of pulleys. 

In nearly every town there is now a station for electric-light- 
ing purposes, and managers of it are finding that they can 
extend the earning capacity of their plants and increase their 
profits by renting power at a time when otherwise their machin- 
ery would be practically idle. We have arranged to have our 



Fig. 91. 




BLOWER AND ELECTRIC MOTOR. 



machines operated by electric motors when desired. In Fig. 
91 will be found an illustration of a motor geared direct to a 
blower, both on the same bed-plate. When preferred, how- 
ever, the motor can be located a short distance away, and the 
power transmitted to the blower pulley by means of a belt. 
Foundries and other industries needing power only to run their 
blowers will find it exceedingly advantageous and economical 
to adopt this plan. Not only will there be a saving in first cost, 
but the operating expense will be much less. 

Furthermore, the motors can have sufficient power to run the 
rattler and other light machines about the establishment. 



422 



THE CUPOLA FURNACE. 



ROOT S ROTARY PRESSURE Br OWERS. 

In the latest improvements in the construction of these 
blowers, the manufacturers assert that they represent the up- 
to date developments in this class of machinery, because with 
an experience of forty years in the construction of rotary pres- 
sure blowers, their improvements mean that they adapt and 
adopt such features as will meet the requirements of the trade, 
and at the same time eliminate what their long experience 
teaches them would be objectionable in the construction of this 
class of machinery. 

They claim that their machines represent the best class of 
workmanship, material and design, the highest efficiency, the 

Fi<:. 92. 




ROOT'S VERTICAL PRESSURE BI OWER. 



greatest durability, and 'a positive guarantee that a given quan- 
tity of air under a given pressure will be delivered with less 
power than any competing machine. 

In the most recent constructions the shape of the blower 
cases has to some extent been changed, and they are now con- 
structed vertical and horizonal as shown in Figs. 92 and 93. 
They are also made with blower and engine on same bed-plate 
or with blower and electric power motors on same bed-plate. 
The following claims are made for it by the manufacturers: 



BLOWERS. 



423 



1. It is simpler than any other blower. 

2. It is the only positive rotary blower made with impellers 
constructed on correct principles. 

3. It is the best, because it has stood the test of years and is 
the result of long experience. 

4. In case of wear of the journals, the impellers will not come 
together and break, or consume unnecessary power, as is the 
case with competing machines. 

5. The princii^les upon which our blowers are constructed 
admit of more perfect mechanical proportions than any other. 




ROOT'S HORIZONTAL PRESSURE BLOWER. 



6. The only perfectly adjustable journal box for this type of 
machine is used. 

7. The gears are wide- faced and run constantly in oil. 

8. The gears and journals are thoroughly protected from 
dust and accident. 

9. Our machine blows and exhausts equally well and at the 
same time, and the motion may be reversed at any time. 

10. All the operating parts are accurately balanced. 

The principles upon which our blower is constructed are so 
radically different from any competing machine that we are 
enabled to adopt proportions that are mechanically perfect, and 



424 



THE CUPOLA FURNACE. 



hence we can speed our machines much faster than any other, 
with a far greater degree of safety. We are not compelled to 
cut down the weight of our blower cases, as other manufacturers 
do, in order to bring the weight of the complete machine within 
reasonable bounds. The distribution of metal in the shafting, 
impellers, gears and cases of all our blowers is perfectly pro- 
portioned, and it is the only rotary positive blower made so 
constructed. 

GARDEN CITY POSITIVE BLAST BLOWERS. 

In Fig. 94 is shown the Garden City Positive Blast Blower, 
manufactured by the Garden City Fan Co., Chicago, II!., many 

Fk;. 94. 




GARDKN CriY POSITI\'E BLAST BLOWER. 



of which are in use in foundries, and for which claims are made 
as follows : 

The operation of our blower is not on the fan principle, in 
which pressure is obtained by a high velocity or speed, but 
when the air enters the case at the inlet and is closed in by the 
vanes of the blower, it is absolutely confined and must be forced 



BLOWERS. 425 

forward until finally released at the outlet, where it must have 
escape or the blower stop if outlet is closed. There is posi- 
tively no chance for loss by backward escapement of air, after 
it once enters the inlet. 

In many respects our blower has points of superiority over 
any positive blower made, and we call your attention to the 
following points : 

1st. It has no £:^ears whatever. No internal parts that re- 
quire attention, adjustment or lubrication. 

2d. It has only two journal bearings that are external to the 
blower casing. They are self-oiling. Easy of adjustment. 

3d. Has no irregular internal surfaces that require contact 
to produce pressure, and add friction. 

4th. Operating parts are always in perfect balance, thus 
blower may be safely run at a higher speed than any positive 
blower made, giving a proportionate increase in efficiency and 
a smaller blower may be used. 

5th. A higher pressure can be obtained than is possible with 
any other. 

6th. The blowers are practically noiseless as compared with 
all other makes. 

STURTEVANT HIGH-PRESSURE BLOWERS. 

Since the publication of the second edition of this work the 
B. F. Sturtevant Co. have perfected and placed upon the market 
a new high-pressure blower, Fig. 95, designed for handling air 
or gas at any pressure below ten pounds per square inch. 
They may be used to advantage in supplying air blast for foun- 
c'ry cupolas, forge fires, smelting furnaces, hardening, temper- 
ing, and annealing furnaces, whether supplied with coal, gas or 
oil; for pneumatic tube systems ; for moving granular material ; 
and in fact for furnishing air or gas for any purpose where the 
maximum pressure does not exceed the limit of ten pounds. 
The blower, which is of the so-called positive type, is manufac- 
tured in a variety of sizes and capacities ranging from five 
cubic feet to over 15000 cubic feet per minute. 



426 



THE CUPOLA FURNACE. 



The blower consists of four principal parts : the cast-iron 
shell or casing, two rotating members, or rotors, and a station- 
ary core. The rotors are held in position by bearings mounted 
on the end plates, and are made to revolve at the same speeds 
being connected by gears. As one of the rotors, called the 
impellers, revolves, it forms pockets or chambers in the annu- 
lar space between the core and the shell which imprison the air 
and carry it from the suction to the discharge, its return being 
prevented by the other rotor. Each pocket, as it nears the 
discharge, is decreased in volume, and consequently delivers its 

air at greater density. 

Fig. 95. 



i 




The other rotor, called the idler because it does no work,, 
simply acts as a valve to allow the impeller-blades to return to 
the suction side of the machine without loss of compressed air.. 
All the work of compressing and moving the air is done by the 
impeller which is mounted on the driving shaft, and no power 
is transmitted through the gears to the idler except that which 
is necessary to overcome the friction of the journals. Because 
all the work is done by one shaft, the load on the engine or 
motor is constant, the gears are relieved of all but a small 
fraction of their usual duty, and the wear is correspondingly 
reduced. 



BLOWERS. 



427 






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428 THE CUPOLA FURNACE. 

Sturtevant electric motors and engines, especially adapted 
for use with these blowers, may be connected to the blowers in 
a number of different ways. 

Air or gas at atmospheric or suction pressure entering the 
blower at the intake is successively imprisoned in the three 
pockets formed by the three blades of the revolving impeller, 
and, since these volumes are reduced as the impeller- blades 
pass into the idler spaces, the air is discharged at any desired 
pressure up to ten pounds per square inch. The volume of 
free air displaced per revolution is constant, the pressure vary- 
ing with the speed and with the resistance to the passage of air. 

The principle upon which the blower operates is clearly 
shown by the diagram, fig. 93, which is a sectional view illus- 
trating the design and inside construction of the blower, fig. 94. 
The extreme high pressure for a rotary blower attained by this 
blower at once brought it into prominence and it has been in- 
stalled in many plants. 

PIQUA POSITIVE BLOWERS. 

Another positive pressure blower, that has attracted con- 
siderable attention of late, is The Piqua Blower. This blower 
is constructed upon the same general principles as the Root's 
and Connerrsville Blowers. In fact all the positive pressure 
rotary blowers are constructed upon the same general principles 
and it is only the material used in construction, and workman- 
ship that makes one more desirable than the other, for each 
delivers about the same volume of air per revolution of the same 
sized blower and requires about the same per cent of power 
to run them. 

FAN BLOWERS. 

The Sturtevant Bloivers. 
A third of a century has elapsed since the Sturtevant Steel 
Pressure Blower was first introduced as an indispensable factor 
in many manufacturing processes. Of the greatest importance 
has been its influence upon cupola practice. Before its advent, 
the rotary blower and the blowing engine were the only devices 



BLOWERS. 



429 



available for the production of blast sufficient for the melting 
of iron. It was at once asserted that a fan blower could not 
create sufificient pressure, was less efficient and less serviceable 
than the rotary blower. But Mr. Sturtevant, with characteristic 
energy and zeal, soon disproved these statements, made the 
fan an active competitor, and soon the worthy successor of the 
rotary blower ; and all this because the merits of the fan were 
emphatically proven, clearly presented and readily appreciated. 

STEEL PRESSURE BLOWERS. 

Although these blowers were originally designed for use in 
connection with cupola furnaces and forges, they are equally 
efficient when employed for producing mechanical draft for 
steam boilers, where high air pressure is required in connection 
with mechanical stokers, for producing the blast in sand blast 

Fig. 96. 




machines, for use in connection with pneumatic tube delivery 
systems, and in fact for any purpose where high pressure is to 
be maintained or where air or gas is to be forced long distances. 
The shell (Fig. 96) is of cast iron, bolted together and pro- 
vided with an outlet. The shaft is of high-grade steel, carefully 
finished, and the wheel and boxes are as described on a suc- 
ceeding page. 



430 



THE CUPOLA FURNACE. 



Number of 


Outside 

Diameter of 

Outlet in 

Inches. 


Diameter and 

Face uf TuUey, 

in Inches. 


Weight, m Pounds. 


Blower. 


Not Packed. 


Packed. 


OOOO 
CO 

o 


2^ 

4 


1% X 1% 
3 X2>^ 


17 

35 

55 


•35 
65 
90 


I 

2 

3 


4% 
5% 
6>i 


3^ X 2l^ 
3^X2% 

4>^x3 


75 

95 

155 


100 
140 

220 


4 
5 
6 


7l^ 

I034 


5 ^iVi 
6% X 4ii 


225 

330 
460 


310 

3^5 
500 


7 
8 

9 

lO 


12 

133^ 
i6 

i8X 


7Kx5^ 

938 X 63^ 
icig X 8 
12^8 X 9% 


695 

870 

1,615 

2,100 


740 

920 

1,680 

2,175 



SfEEL PRESSURE BLOWERS ON ADJUSTABLE BED WITH COMBINED 
UPRIGHT ENGINE. 

This type of machine (Fig. 97) represents the acme of con- 
venience and economy. It may be shipped ready for immediate 
operation, and may be used in any location to which a steam 
pipe can be conducted. The merits of the adjustible bed have 
already been pointed out. Its combination with an upright 
engine insures perfect alignment, rigidity, ease in adjustment, 
perfect control over the tension of belts, and, when desirable, 
an instantaneous change in the speed of the blower independ- 
ently of any portion of the plant. 

Both of the styles of the engines employed are identically 
the same in design, workmanship and material as the regular 
automatic engines. The double enclosed upright engine is 
peculiarly fitted for this service. All the running parts are 
thoroughly protected from the dust that forms an inherent part 
of the atmosphere in or about any foundry or forge shop. The 
oil-cups are all placed upon the exterior of the frame, so that 
continuous oiling is possible without the repeated opening and 
closing of the door. The short stroke, the perfect balance of 



BLOWERS. 431 

the reciprocating parts and the large wearing •surfaces make 

Fig. 97. 




high rotative speed possible and render this engine unexcelled 
for the purpose for which it is designed. 







4 to 8 oz. Pressure. 






8 to 12 oz. Pressure. 




Number 


















of 
Blower. 


Style 
of Engine. 


Diameter 
of Cylinder. 


Stroke. 


Weight in 
Pounds. 


Style 
of Engine. 


Diameter 
of Cylinder. 


Stroke. 


Weight in 
Pounds. 


4 


4 


4 


1,300 




4 


3 


1,650 


5 


.£f 


5 


5 


1.750 ! 


bo 


5 


4 


2, ICO 


6 


0. 

— 
"5) 


6 


6 


2,300 


0. 

T3 


6 


5 


3.500 


7 


m 


7 


7 


3.650 


_o 

c 
U 

3 

3 





6 


5 


4,050 


8 
9 

ID 


Double 
Enclosed 
Upright. 


6 
6 

7 


5 
5 
5 


5.500 
6,300 
7.950 


7 
7 
8 


5 

5 


5.400 
6,400 
8,6co 



ELECTRIC STEEL PRESSURE BLOWERS. 



Electric blowers of this type are obviously applicable for all 
purposes for which the ordinary form of steel pressure blower 
may be employed. The fact that in the case of blowers with 



432 THE CUPOLA FURNACE. 

direct-connected motors it is possible to place them wherever 
most convenient, and then make connection by wire, is most 
suggestive of their universal adaptability. All connecting belts 
and shafting, or the presence of a special engine and the neces- 
sary steam piping, are thus avoided. The blower is usually 
readily portable, and therefore easily adapted to changed con- 
ditions. The electric steel pressure blowers are principally 
used for the blowing of forge fires and cupola furnaces. 

Fig. 98. 




although equally serviceable for any work for which the regu- 
lar type is adapted. 

The general construction of these blowers is evident from the 
accompanying illustration. Fig. 98. 

In the smallest sizes the motor is of the bi-polar type, circu- 
lar in form, extremely compact and attached directly to the 
side of the blower, which is otherwise perfectly regular in its 
character. 

Where the atmosphere is free from dust, the open type may 
be employed. Otherwise, the enclosed construction is prefer- 
able. This is especially designed for foundry work, and may 
be introduced in either of two forms. That is, the motor may 



BLOWERS. 433 

be adjustably attached to the fan; or the motor, with its en- 
closing ends, may be independently mounted, and the fan 
attached in such manner that it may be turned to discharge in 
any direction. 

The largest sizes of electric steel pressure blowers are 
equipped with multi polar motors of the independent circular 
type. This form of motor is placed upon a high bed, which in 
connection with the fan to which it is bolted serves as an ex- 
tremely solid foundation. 

In the belted arrangement the same type of motor is em- 
ployed. This form of construction is desirable where the 
speed of a direct connected motor would of necessity be ex- 
cessive, or where for certain reasons such an arrangement 
would be undesirable. 

Dififerent-sized motors may be fitted to the same blower, 
thereby making possible a great number of combinations, with 
speeds and cai)acities dependent upon the current and the size 
of the motor. These electric blowers are regularly made with 
bottom horizontal discharge, but may be made to discharge 
either upward, downward, or horizontally at the top, when so 
ordered. In asking for estimate state clearly what work it is 
de-ired the blower should do, and give the voltage of the 
current available. 

BUFFALO STEEL PRESSURE BLOWER. 

In Fig. 99 is shown the latest improved construction form of 
the Buffalo Steel Pressure Blower, for cupola furnaces and forge 
fires. A distinguishing feature of this blower, common to 
those of no other manufacture of the same type, is the solid 
case, the peripheral portion of the shell being cast in one solid 
piece, to which the center plates are accurately fitted, metal to 
metal. It will thus be seen that the objectionable and slovenly 
" putty joint " is entirely dispensed with. Ready access to the 
interior of the blower, without entirely taking it apart, is also 
thus afforded. With blowers of other manufacture, the "putty 
joint" feature of the shell or casing is an indispensable adjunct, 
28 



434 



THE CUPOLA FURNACE. 



although it is a construction-point which is, at the best, some- 
thing to be avoided in an efficient machine. 

The Bufifalo Steel Pressure Blower is designed and con- 
structed especially for high pressure dut)', such as supplying 
blast for cupolas, furnaces, forge fires, sand-blast machines, for 
any work requiring forcing of air long distances, as in connec- 
tion with a pneumatic tube delivery system. It is adapted for 
all uses where a high pressure or strong blast of air is re- 

FiG. 99. 






.^-if / M: 




Slt-EL I'KESSUKE Kl.OWEK. 



quired. The journals are long and heavy, in the standard 
ratio of length to diameter of six to one, and embody a greater 
amount of wearing surface than those upon the blower of any 
other construction. Attention is directed to the patented jour- 
nals and oiling devices employed on this blower, which are 
unique features. The bearings are readily adjustable, and any 
wear can be taken up, which is an important point attending 
the durability and quiet running of a perfect machine. 

The Bufifalo Steel Pressure Blower possesses the fewest num- 
ber of parts of any like machine; in fact, the blower is prac- 



BLOWERS. 435 

tically one piece, so that under any service the bearings 
invariably are in perfect alignment, vertically and laterally, with 
the rest of the machine. In the items of durability, smooth 
running and economy of power, it is thus rendered far superior 
to any blower with the so-called universal journal bearing 
which is commonly employed. 

In every point of construction the greatest pains have been 
taken to simplify all parts, and at the same time to give them 
the greatest strength. To adjust, repair and keep in order a 
BufTalo Blower is a very small matter and readily understood 
by a machinist of average ability. 

For obtaining the best results from a blower of given size, 
when used for melting iron in foundry cupolas, much depends 
upon the proper lay-out of the blast piping between the blower 
and the cupola, and also upon the proper proportionment, ar- 
rangement and design of the cupola tuyeres. Several forms of 
cupolas are now upon the market, economical in the use of fuel 
and fast melting, which are the points most sought for in cupola 
construction. It is a common but erroneous idea that a blower 
large for the work will give better results, in a given diameter 
of cupola, than a smaller one. In the tables which accompany 
the blower we give the proper sizes of blower for different 
diameters of cupolas; but it must be borne in mind that if the 
tuyerage is not of sufificient area, or if the blower has to be 
located at some distance from the work to be accomplished, 
these points enter for consideration. Frequently foundrymen, 
when experiencing difficulty in obtaining satisfactory melts, 
throw the whole cause of the trouble upon the blower, when 
the fault does not lie at this point. It is safe to say that failures 
are due more largely to the mism.anagement of a cupola and 
improper application of the blower than to any other cause. 

The BufTalo Steel Pressure Blower is especially adapted for 
foundry cupolas, and is guaranteed to produce stronger blast 
with less expense for power than any other. 



436 



THE CUPOLA FURNACE. 



BLOWER ON ADJUSTABLE BED, AND ON BED COMBINED WITH COUNTERSHAFT. 

Unless considerable care is taken in putting up countershafts^ 
and some special attention is given to keep them in. perfect 
alignment, trouble is often experienced, especially in keeping 
the belts on the larger sizes of blowers, on account of the great 
speed at which they have to run to produce high pressures. 
To overcome such features, this house designed the adjustable 
bed, and the adjustable bed combined with countershaft ar- 
rangements, which is illustrated in Fig. lOO. The blower on 
adjustable bed, alone, without the countershaft, is very con- 

¥\G. lOO. 




HI.OWEK AXD COUNTERSHAFT. 



venien.t for taking up the slack in belts while the fan is in 
motion and driven by belt from main line. 

In Fig. lOO is shown the latest construction form of Buffalo 
Steel Pressure Blower on adjustable bed with combined coun- 
tershaft. Its use will be found to result in a decided saving in 
the wear and tear upon belts, which, in a short time, more 
than justifies the extra initial expense of the arrangement. The 
cost will be found liitle in excess of ordinary method, and a 
few turns of the nut on the end of the adjusting screw, which is 



BLOWERS. 437 

clearly shown directly under the outlet of the blower, after first 
loosening the holding-down bolts, which should afterward be 
re-tightened, accomplish, in a very few moments, what, previous 
to the introduction of this apparatus, has caused considerable 
delay and annoyance. It will readily be seen that the usual 
frequent relacing of belts, to make them sufficiently tight to 
avoid slipping, is hereby entirely obviated. 

Positive alignment of the countershaft with the shaft of the 
blower by this arrangement causes the belt to track evenly, run 
smoothly and avoid the usual wear by their striking against the 
hanger or side of the blower. As will be readily appreciated, 
the tightening screw gives the same uniform tension to both 
belts, and this may be regulated at will of operator. A tele- 
scopic mouth-piece, as is shown by the cut, is placed upon 
each blower purchased in this form, which enables the machine 
to be moved upon its bed without any disarrangement of the 
blast piping. 

Especial attention is called to the fact that the arrangement 
of blower on adjustable bed combined with countershaft, as 
illustrated in Fig. lOO, occupies the smallest amount of space 
consumed by any apparatus of this kind manufactured in the 
world. Ordinary tight and loose pulleys are placed upon the 
countershaft from which the power is transmitted to the coun- 
tershaft of this apparatus. When this feature is not desirable, 
which is often the case where power is transmitted from the 
main line without the intervention of a countershaft, the adjust- 
able bed countershaft may be furnished with the blower, so 
that it will extend at the right or left, as desired, and the tight 
and loose pulleys are then placed thereon ; we then' have a 
right or left hand apparatus. The space between the two 
pulleys which drive the blower is not wide enough to permit of 
the introduction of tight and loose pulleys. 

BUFFALO BLOWER FOR CUPOLA FURNACES IM IRON FOUNDRIES. 

In the following table are given two different speeds and 
pressures for each sized blower, and the quantity of iron that 



438 



THE CUPOLA FURNACE. 



may be melted per hour with each. In all cases, we recom- 
mend using the lowest pressure of blast that will do a given 
work. Run up to the speed given for that pressure, and regu- 
late the quantity of air by the blast gate. The proportion of 
tuyerage should be at least one-ninth of the area of cupola in 
square inches, with not less than four tuyeres at equal distances 
around cupola, so as to equalize the blast throughout. With 
tuyeres one-twentieth of area of cupola, it will require double 
the power to melt the same quantity of iron, and the blast will 
not be so evenly distributed. Variations in temperature afTect 
the working of cupolas very materially. Hot weather requires 
an increase in volume of air to melt same quantity of iron as in 
cold weather. 



Table of Speeds and Capacities as Applied to Cupolas. 





in 


T3 ■•-' 







* u 






*o 


t u 

u 






o 

a 

il 

3 S 

a* 


rt HH 


•SO 


S ■" • '-''9 


m 

U U IH 


c . 

so 


d s . 

a, 




PI 

u 1- 


T^ 


C/2 


Q 


fu 


en 2 


U 


p-( 


ca; 


^-. 


u 


4 


4 


20 


8 


4732 


1545 


666 


9 


5030 


1647 


717 


5 


6 


25 


8 


4209 


2321 


773 


10 


4726 


2600 


867 


6 


8 


30 


8 


3660 


3093 


951 


ID 


4108 


3671 


1067 


7 


14 


35 


8 


3244 


4218 


i486 


10 


3642 


4777 


i6fe8 


8 


i8 


40 


8 


2948 


5425 


2199 


10 


33>o 


6082 


2469 


9 


26 


45 


ID 


27«5 


7818 


3203 


12 


3260 


8598 


3523 


ID 


36 


55 


10 


2195 


11295 


4938 


12 


2413 


12378 


5431 


II 


45 


6S 


12 


1952 


16955 


7707 


14 


2116 


i«357 


«35« 


III/^ 


55 


72 


12 


1647 


22607 


10276 


14 


1797 


25176 


1 1 144 


12 


75 


84 


12 


1647 


25836 


1 1 744 


14 


1797 


28019 


12736 



"a. b. c." steel pressure blowers. 

The A. B. C. Steel Pressure Blowers of the American Blower 
Co. are especially designed and constructed for delivering air 
at high pressure. They are, therefore, adapted for supplying 
blast for cupolas, forges, etc., and the following claims are 
made for them : 



BLOWKRS. 439 

Centrifugal Pressure Blowers have many advantages not 
possessed by blowing engines, rotary or so-called positive 
blowers, or other devices built for the same class of work. 
These advantages may be briefly summarized as follows: 
I. The cost is from one-fourth to one-third the cost of a 
rotary blower. 2. It weighs about one-eighth. 3. Occupies 
less than one-third the floor space. 4. Requires from one-third 
to one-half the power to produce the same results. 5. Can 
produce a steady pressure of 20 ounces per square inch, which 
is the maximum required for any furnace or cupola. 6. The 
volume discharged is proportional to the resistance, automat- 
ically increasing if another cupola or furnace is added. The 
power required to drive the blower is almost proportional to 
the volume, being little more than the friction of the bearings 
when the blast is closed off. With a rotary blower, adjust- 
ments have to be made for every change of conditions and the. 
power remains at the maximum whether the blast is off or on. 
7. The mechanical efificiency is from 50 to 85 per cent, greater 
(varying with the age of the rotary blower), due to wear of 
the impellers, gears, and other mechanical leakages and lost 
motion. 8. A Centrifugal Blower automatically adjusts itself 
to the work, always producing results with the highest possible 
efficiency, whereas the rotary blower is dependent entirely upon 
the skill and intelligence of the operator for the results attained. 
9. Centrifugal Blowers have run for years without any expense 
for repairs. Rotary blowers require constant attention and fre- 
quent overhauling to keep the impellers in such condition as 
to reduce excessive leakage. 10. There is no pulsation to the 
blast, which is even, smooth, and steady under all conditions — 
a most desirable condition. 11. The term "Positive Blower," 
so commonly applied to rotary blowers, or those having impel- 
lers revolving in close proximity to one another, is very mis- 
leading. They are not "positive" in any sense of the word. 
The impellers cannot rub together; if they did they would 
soon wear so there would be no contact. As the bearings and 
gears wear the leakage becomes greater. The whole machine 



440 



THE CUPOLA FURNACE. 



has to be taken apart to make repairs. It is made of very 
heavy and cumbersome parts, hard and awkward to handle, 
making emergency repairs difficult, if not impossible. The 
Centrifugal Blower is light and simple in construction, easily 
accessible, requires no repairs (barring accidents) except re- 
babbiting the bearings ; is equally as positive in delivery, and 
far more economical and simple to operate. That this is the 
general opinion is proven conclusively by the vastly greater 
number of Centrifugal Blowers in use than any other type. 



Fig. ioi. 




In Fig. IOI may be seen one of these blowers in a foundry, 
illustrating position of blower-pipe connection, method of ap- 
plying power, etc. 

Blowers of this type are designed to be driven b)' direct con- 
nected electric motors. Pressure blowers of standard propor- 
tions run at speeds altogether too fast to be electrically driven, 
but by increasing the diameter of the impeller and altering the 
proportions of the other parts, the speed can be made to con- 
form with that of any motor; and at the same time the blower 
will produce any pressure and deliver any volume of air within 
the possibilities of accomplishment with centrifugal pressure 
blowers. 

These blowers are built entirely of steel, amply strong for 



BLOWERS. 441 

the severest conditions. They are far more desirable than the 
smaller high-speed blowers which are driven by belt. 

The motor is attached by a flexible coupling, which avoids 
any trouble from imperfect alignment through the use of four 
bearings in a row, two of which are on the motor and two on 
the blower. 



CHAPTER XXVI. 

FOUNDRY TRAMRAIL. 

Foundry transportation is receiving more careful attention 
to-day than ever before. For the foundry the day of the wheel- 
barrow and industrial track is over and, on account of their 
many disadvantages and costly operation, they are becoming 
obsolete. 

The mostefificient method thus far used is an overhead tram- 

FlG. I02. 




TRAMRAIL OVER THE STORAGE YARD — WITH LIFTING MAGNET CARRYING COKE. 



rail or trolley track as it is sometimes called. By means of 
this tramrail one man will handle easily loads weighing up to 
one ton. 

Briefly described, the tramrail consists of a steel I beam of 

(442) 



FOUNDRY TRAMR\IL. 



443 



standard section, running on tlie lower flange of which is a four 
wheel trolley. Suitable hangers can be made to attach this 
rail to the overhead roof trusses or other supports. An I beam 
makes an inexpensive form of rail in that the hangers neces- 
sary to support it can be placed as far apart as twenty feet, and 
a ton load be carried. 

As used in the average foundry, the main line extends out 
along the wall in the storage yard with branch <^witches and 
tracks running to the piles of coke, scrap and pig. A section 
of the rail is placed on the elevator and on the platform, and a 

Fig. 103. 




CARRYING COKE FROM THE STORAGE YARD TO THE CHARGING FLOOR. 



loop around in front of the charging door of the cupola. One 
man in the yard will load self-dumping buckets with coke, or 
racks with pig or scrap, and shove them over the tramrail in the 
yard to the elevator. Here the yard rail and the section of the 
tramrail on the elevator come to a common level and the load 
is shoved, still on the trolley, on to the elevator, is raised and 
pushed ofT on the trolley to the loop in front of the charging 
door. Scrap and coke may be dumped directly into the cupola 
and in the case of pig the rack or cradle is run near the door 
and the pig thrown into the cupola where wanted. 

The ingredients for the entire charge may be run up to the 



444 



THK CUPULA FURNACE. 



platform and stored, and when the heat is on, the yard man may 
be used on the platform. In some cases an hour's melt may 
be stored and one man left in the yard to bring up the charge 
for the next hour. 

As the most efificient method is to weigh each charge, a 
scale may be inserted in the rail and the load weighed as it 
moves along. The scale is usually placed in the rail in the 

Fig. 104. 




CHARGING SCRAP BY MEANS OF TKAMRAIL. 

yard just before the load passes to the elevator. By this 
method no rehandling of the pig, coke or scrap for weighing or 
charging is necessary. 

In foundries of larger capacities, the tranirail may extend 
out over the yard on the same level as the rail on the platform, 
an electric trolley and hoist be provided, and for lifting pig and 
scrap, and electric magnet. By means of this system one man 



FOUNDRY TRAM RAIT.. 



445 



in the trolley cage and one or two men in the yard will not 
only convey to the charging floor the ingredients for the heats 
up to lOO tons, but will unload the incoming cars of pig and 
scrap. 

We know of one installation of this kind wherein three men 
and an electric tramrail are all that are necessary to convey pig, 
scrap and coke for lOO tons daily melt as against twenty-three 
men in the old way of wheelbarrows, industrial tracks and cars^ 

Fig. loe. 




CHARGING COKE IN A DUMP BUCKET SUSPENDKD FROM TRAMRAIL. 



A tramrail for carrying molten metal from the cupola is a 
labor-saving appliance well worih consideration. 

Starting in front of the cupola spout a loop should extend to 
the main line of the tramrail system and by means of curves 
and switches be so designed as to enable a load to make a con- 
tinuous loop so that full ladles pass one way and come back 
empty to the cupola a different way. This is necessary as it is 
not good practice to have a full ladle wait for an empty one to 
pass out of its way. If a continuous loop of rail is not installed 



446 



THE CUPOLA FURNACE. 



there should be frequent cut-outs or switches enabling the full 
to pass the empt)' ladle. 

For continuous pouring, the best way is to provide a tilting 
spout on the end of the regular .cupola spout. By means of 
this, an empty ladle may be placed directly against the ladle 
receiving its metal, so that when filled, the tilting spout is tip- 
ped so that the metal runs into the waiting ladle. This does 
away with tapping the spout, insures a continuous stream and 
consequently better mixed metal. 

Ladles containing up to 1500 lbs. of metal are shoved by 
one man to any of the floors and poured direct mto the flasks 

Fig. 106. 




LADLES BEING ULLED AT THE C'JPOLA SPOUT. 



if the castings are heavy, or into the ladles of the moulders at 
the floors if the castings are light in weight. 

It is admitted, that the larger the volume of metal carried, 
the longer it will stay hot, so that if large bull ladles are carried 
to the floors in place of one or even two man shank ladles the 
metal will be delivered to the flasks at a higher temperature, 
cleaner and more uniformly mixed than by any other method 
thus far designed. 

Theoretically, if it were possible to bring the flasks up under 
the cupola spout better castings would result. Again, if it 
were possible to place a number of small cupolas over the 



FOUNDRY TRAMRAIL. 447 

foundry, one at each floor, better castings would result. Both 
of these methods of course are impossible, but what can be 
done is to carry the metal in large bulls from the cupola to the 
floor. 

It should be borne in mind, that an excess ladle capacity of 
33/^ per cent, is absolutely essential in order that the ladle 
may be quickly moved about without any possible danger of 
slopping the metal. 

In addition to carrying the charge and supplying metal to 
the floors, tramrails can be used to do nearly all of the carrying 
around the foundry and a well designed system, well installed 
and put to all the uses for which it is so well adapted, will pay 
for its original cost several times each year it is used. 



I 



m 



NDEX. 



A. 



441 



Abendroth Bros., cupola report of, 
292 
tuyeres in the cupola 
of, 58 
Adjustable tuyeres, 60, 61 
Air, amount of, required for combus- 
tion of fuel. -IIU 
and coke, ratio of, 220, 221 
capacity for moisture, 217, 218 
chamber, 5, 29-31 
chambers, connection of, with 

blast pipes, 399-401 
dry, for the cupola, 223, 224 
effect of heat on, 218, 219 
gauges, 389 
temperature of, 220 
Alloys, melting of. 279 
American Bio ^er Co., steel pressure 

blowers of, 438-441 
Angle irons, arrangement of, 39-41 
Anthracite coal as a cupola fuel, 230- 
238 
pounds of iron melted 
with one pound of, 
113 
quantity of, for bed, 98 
Apron, 90 
Art iu melting, 280-290 



B. C. steel pressure blowers, 438- • Bedstead work, small cupola for, 175, 

176 
Belgium, small cupolas of, 178, 179 
Belt air chamber, connection of, with 

tuyere, 401 
Bessemer steel, melting pig iron in 

the manufacture of, 'St"! 
Bituminous coal as a cupola fuel, 252- 

254 
Blakeney cupola, 376-378 

tu\ere, 50, 51 
Blast, '1U8 

adding steam or water to, 222, 

223 
admission of, to air chamber, 31 
best way to put on, 110 
closing the tap-hole before put- 
ting on, 11(1, 111 
delay in putting on, 388, 389 
driving of, to the center, 15 
dry, Gayley, 223 
failure of healing, 215 
fallacy of the theory of heating, 

209 
freezing the, 215-224 
furnace, fuel required for, 1 
gates, 404-406 
gauges, 406-408 
hot, theory of obtaining, 210 
in melting, 4(i8-413 
machines for supplying, 408 
moist or dry, 222, 223 
moisture in, 210, 217 
old theory of, 15 
-pipes, 394-103 

and blast; 394-413 
connection of, with air-cham- 
bers, 399-401 
with cupolas, 

397, 398 
with tuyeres, 
399 
diameter of, 397-403 
and area of, 398 
explosion in, 4(16 
long, cause of poor melting, 

4(i2 
materials for, 395 



BAILLOT cupola, records of ex- 
periments made on a, 214 
cupolas. 210-213 
Baldwin Locomotive Works, swing- 
ing crane with magnet attached at, 
313 
Bancroft, M. H., on weather and the 

output of the cupola, 217-222 
Banking a cupola, 286-288 
Basin spout, 316 
Bed, 98-1(10 

arrangement of, 95, 96 
burning up the, 96, 388 
leveling the top of, 103 
raising or lowering a, 99, 100 
uneven burning of 201 
weight of fuel required for, 100 

29 ( 449 ) 



450 



INDEX. 



Blast-pipes, table showing necessary 
increase in diameter for 
difFert-nt lengths of, 396 
underground, 394 
positive and non-positive, 408, 

4(i9 
supply of, 12 
taking off the, during a heat, 

285. 28ti 
time for charging the iron before 
putting on, 1U9-111 
Blossburg coke, 240 
Blower and counter-shaft, 436 

connections of tuyeres with, 5 
load on, 219, 220 
placing a, 4(l3, 404 
Blowers, 414-441 
types of, 414 
Bod, making a good, 118 
material 117-119 
size and shape of, 119 
steel bar for cutting away the, 116 
sticks, 116, 117 

support for, 121 
wet, explosion of iron caused by, 
302. 303 
Boiler-plate casings, 13, 14 
Bulling, cleaning iron by, 270, 271 

or foaming slag, 331 
Boshed cupola, lining of, 132 
Bottom doors, 4, 25, 26 

devices for raising, 26, 27 
supports of, 4 
hard ramtntd, 388 
height of, 25 
of cupola, height of, above 

moulding floors, 3 
plate, 4, 41 

removing props from the, 122 
sand, 81, 282 
wet, 3S8 
tuyere, 61-64 
Brackets, arrangement of, 39-41 
Brass, melting of, 279 
Breast building a, 90 

plate, 90 
Brick for lining. 1.34, 135 

lining, common red, 335, 336 
stack cupolas, 13 
Bricks for cupolas, 37 
Bridge, breaking away a, 123 
Browne & Sharp Manufacturing Co., 

stockyards of, 313, 314 
Buckeye heater or oil torch, 97, 98 
Buffalo blower for cupola furnaces in 
iron foundries, 4;-47, 438 
Forge Co., banking the cupola 
of, 286-288 



Buffalo School Furniture Co., explo- 
sion at, 
306, 307 
tuyeres in 
the cupola 
of, 69 
steel pressure blower, 433-437 
Burns, treatment of. 332 
By product coke, 251, 252 
By ram & Co., cupola report of, 293 

pALUMET cupola, 152-155 
v^ Calvin, Dan., description of a 
small portable cupola by, 168- 
170 
Canada Car Co., records of experi- 
ments made on a cupola of the 
Baillot system, 214 
Carbon, effect of, on iron, 268 
Carnegie Steel Works, device for 
charging cu- 
polas at, 325, 
326 
large cupolas at, 
156, 157 
Cars for removing dump, 124 
Casing, 27-29 

greatest wear on, 27 
lining for, 6, 7, 37 
rusting of, 40 
strain upon, 27 
Casings of cupolas, 4, 5 

of stacks, 5 
Cast iron blast pipes, 395 

quantity of, that can be 

melted in a cupola, 272, 273 

size and weight of, that can 

be charged, 273 

Castings, report on, 296 

Center 1)last tuyere, 61-64, 159, 160, 

412, 413 
Centrifugal blower, 440 
Charcoal fuel, 228-2.30 
Charge, weighing the, 444 
Charges, heavy, division of, 105 
placing the, 103-1U7 
small, for a cupola, 327, 328 
Charging, 100-103 

and melting with anthracite 

coal, 232, 233 
aperture, location of, 28, 29 
coke, rule for, 245, 246 
cupola slate for, and cupola re- 
port, 297 
cupolas, devices for, 325-327 
door, 6, 29 

carrying coke from storage 
yard to, 443 



INDEX. 



451 



Charging door, iudestructible wire 
screen, 147, 148 
flux, 1(17 
Cbenney tuyere, 56 
Chill-mould, damp or rusted, explo- 
sion of molten iron when poured 
into, 304 
Chipping out, 125, 126 

protecting the melter 
when, 329, 330 
Cinder, brittle, 259 

tendency of, 259, 260 
Clay sands for bottom, 81 
Clays for daubing, 127 

for spouc linings, 87 
Cleaning iron by boiling, 270, 271 
Climate and hot iron, 223 
Coal and coke, mixture of, 236, 237 
wood, bad melting caused 
by, 198, 199 
anthracite, as a cupola fuel, 230- 
238 
charging and melting with, 

232, 233 
first use of, 231 
pounds of iron melted with 

one pound of, 1 13 
report from foundries show- 
ing per cent, of, consumed 
in melting, 234 
size of, for melting, 234, 235 
bitummous, as a cupola fuel, 252- 

254 
diflference in, 231 
for lighting up, 95 
Coke and coal, mixture of, 236, 237 
by-product, 251, 252 
carrying of, from storage yard to 

charging door, 443 
charging of, in a dump bucket 

suspended from tramrail, 445 
Connt-llsville, pounds of iron 
melted with one pound of, 
113 
conveyance of, to scaffold, 23 
custom in the early days of melt- 
ing with, 242-244 
difFt-rence in, 244 
economy in melting with, 241 
first manufacture of, 238 

shipment of, 238 
for cupola, :i38-251 
lighting up, 95 
good foundry, requirements in 

the manufacture of, 211 
in summer and winter, 221, 222 
ovens, first coke made in, 238 
per cent, of, to iron, 250 



Coke, poor, remedy in melting with, 
247 
quantity of, for bed, 98 
reason for the variation in the 

quality of, 245 
reports of melting with, 250 
rule for charging, 245, 246 
seventy-two liour, 244, 245 
Sol way, 251, 252 
Colliau cupola, 18-20, 137-141 
hot-blast cupola, 205, 206 
tuvere, 56 
Combination bod-stick, 117 
Connellsville coke, first record of use 
of, 238, 239 
pounds of iron melt- 
ed with one pound 
of, 113 
reports of melting 
with, 250 
Connersville cycloidal blower, 415- 

421 
Construction of a cupola, 22-44 
Cost of melting, 298-301 
Crandall improved cupola with John- 
son patent center-blast tuyere, 374- 
376 
Cross spout, 316-318 
Cupola accounts, 291-301 

art of melting in a, 280-290 
banking a, 286-288 
Blakeney, 378 
blast, moist or dry, 222, 223 
blower placed near, 402 
boshed, lining of, 132 
bottom, 2 

ht-ight of, 25 
breast and runner, Moor's patent, 

33^> 
brick, 37 

bridgfd, section through, 130-132 
bridging of, 15 
casing, 27-29 
charging a, 100-103 
cheap, small, movable, 170, 171 
coke, 238--i51 
commencement of melting in a, 

108, 109 
construction of a, 22-44 
Crandall improved, with John- 
son patent center-blast tuyere, 
374-376 
does it pay to slag a, 264, 265 
drv air for, 223, 224 
E.'j. R . 150-152 
expanding, 342-344 
fluxing a 107 * 

of iron in a, 258-271 



452 



INDEX. 



Cupola for melting tiu-plate scrap, 
278, 279 
foundation, 28, 24 
fuels, 225-257 
furnace, 1-7 

advantages of, 1 

description of, 2-7 

first, used in this country, 
8, 9 
Gmelin's, 361-3G3 
Greiner's patent economical, 367- 

369 
height of a, 28 
Holland, 206-210 
hoods, 385, 386 
Ireland's, 344-346 

center blast, 346-348 
Jumbo, 371-374 
Keep sectional, 171-173 
McShane large, 157-159 
Mackenzie, 357-361 
management, 77-136 

requirements for, 283, 284 
melting capacity of a, 29 

with charcoal in a, 229, 230 

z .ne of, 98 
number of men required to man 

a, 323-336 
Newten, 141-144 
old style stave, 338-341 
on wheels, 176, 177 
Paxson Colliau, 144-148 
truck and track, 176, 177 
proper location of, 22 
Pevie, 363-365 
piiks, 126 

placing tuyeres in a, 411, 412 
plain, round, 21 
practice, oil in, 209, 210 
reason why a, works better on a 

rainy day, 222 
reservoir, 342 
, scrap, charging of, 103, 104 
scraps, 387-395 
sectional view of, 38 
slate for charging and cupola re- 
port, 297 
small charges for a, 327, 328 

for bedstead work, 175, 176 

portable, 168-170 

value of, as a money maker 
or saver, 164, 165 
space theory of, 246 
stationary bottom, 174, 175 
Stewart's, 365-367 
stock, getting up, 308-314 
g supports, 24 
swivel, 166-168 



Cupola tank or reservoir, 354-357 
tuveres, 45-76 

utilization of heat from, 202-205 
Voisin's, 348-350 
warming up a, 196-198 
weather and the output of the, 

217-222 
West's large, 159-161 
what a, will melt, 272-279 
Whiting, 148-150 
wonderful, 254-257 
Woodward's steam jet, 350-354 
Cupolas, Baillot's, 210-213 
Colliau, 137-141 
connection of blast-pipes with, 

397. 398 
devices for charging, 325-327 
for heavy work, tuyeres in, 68 
forms and sizes of, 2 
foundations of, 2 
heights of, 13 
high, importance of, 137 
Homestead larjje, 156, 157 
hot blast, 202-214 
improvements in, 8-21 
large, 156-163 

advantages and disadvan- 
tages of, 161-163 
modern, 137-155 
of different diameters, height and 

size of door for, 29 
scientificaliv designed, 337-378 
small, 164-186 

bod for, 118, 119 
of Europe, 178, 179 
spark catching devices for, 379- 

393 
steam jet, 369-371 
trouble in slagging, 263, 264 

DAUBING, 126-128 
excessive, 130 
material, 127, 282 

from pieces of fire-brick, 
135, 136 
new method of mixing, 332- 

334 
object of application of, to 

lining, 128, 129 
thickness of, 130 
Doherty cupola, 17, 18 

tuyere, 48, 49 
Doors, devices for raising, 78 
dropping the, 80, 81 
props for, 78. 79 
pulling up the, 78-80 
table giving height and size of, 
29 



INDEX. 



453 



Double spout, 315, 310 
tuyere, 57, 58 

Draw front cupola, 8-10 

Drop bottom cupola, 11, 12 

Dropping the doors, 80, 81 

Dry air for the cupola, 223, 224 

Drying the lining, 77, 78 

Dump, breaking up the, 123 
picking over the, 124, 125 
removing the, 25, 124, 125 

Dumping, 122, 123 

t^ J. E. cupola, 150-152 
^, Electric Controller and Supply 
Co.. lifting magnet of, 
311-313 
steel pressure blowers, 431- 
432 
Elevated stockyards, 313, 314 
Elevator, 23 
Elevators, 309-311 

England, management of small cupo- 
las in, 171 
use of tanks in, for mixing irons, 
356 
Europe, small cupolas of, 178-180 
Examples of bad melting, 181-201 
Expanded tuyere, 47, 48 
Expanding cupola, 342-344 
Explosion of molten iron, 302-307 
Explosions in blast-pipes, 406 

FAN blowers, 428-441 
load on, 219. 220 
Fire brick, daubing material from 
pieces of, 135, 136 
clay for daubing, 127 

soaking of, 129, 130 
-proof scaffolds, 23, 41-44 
sand, 81 
Eloor, wet, muddy, explosion of iron 

caused by, 3(i3 
Fluor spar, use of, as flux, 269, 270 
Flux, charging of, 107 
definition of, 258 
effect of. upon iron, 261 
use of fluor-spar as, 269, 270 

marble spalls as, 265, 266 
shells as, 265 
Fluxes, action of, on lining, 261-264 
influence of, upon front material, 

91 
materials used as, 258 
Fluxing iron in a cupola, 258-271 
limestone in large quantities for, 
259-261 
Foundations of cupolas, 2, 23, 24 



Foundries report from, showing per 
cent, of coal consumed in melt- 
ing, 234 
troubles in, 280 
Foundry, retaining heat in a, 328, 329 
tramrail. 442-447 
transportation in, 442 
work, general, best practical re- 
sults for. for melting, 391 
Freezing the blast, 215-224 
Front, 90-92 

drying the, 91 
material for, 90 

poor, troubles due to, 91 
too wet, 91 
putting in the, 90, 282 
Fuel, 113-115 

amount of air for combustion of, 

410 
charging of, 100, 101 
consumption of, in a double tuy- 
ere cupola, 58 
in various fur- 
naces, 1 
effect of too heavy charges, 102 
for cupola, 1 
gas and liquid, 225-228 
misstatements regarding. 114- 115 
utilization of greatest amount of 

heat from, 282 
weight of charjics of, 103 

required for a bed, 100 
Fuels, cupola, 225-257 

mixed, heats melted with, 236, 
237 
Furnaces, various, consumption of 
fuel in, 1 

GALVANIZED sheet iron scrap, 
melting of, 277 
Garden City positive blast blowers, 

424, 425 
Oas and liquid fuel, 225-228 

-house coke, 241 
Gates, charging of, 103, 104 
Gayley dry blast, 223 
Gebhard, Judge, early use of coke by, 

238 
Getting up cupola stock, 308-314 
Gmelin, Dr. Otto, cupola of, 361-363 
Gould & Eberhardt, cupola scaffold 

in the foundrj' of, 44 
Great Britain, small cupolas of, 178 
Green patented positive pressure 

blower, 415 
Greiner patent economical cupola, 
367-369 
tuyere, 59, 60 



454 



INDEX. 



HAND ladle-work, mauagement of , 
111 
Heat, effect of, on air, 218, 219 

production of, by consuming 

escaping gases, 59 
retaining the, in a foundry, 328, 

329 
taking off the blast during a, 285, 

286 
utilization of, from cupola, 202- 

205 
waste, 221 

utilization of, 1, 28 " 

Heater or oil torch, 97, 98 
Heats melted with mixed fuels, 236, 

237 
Height of cupola, 28 

bottom, 25 
tuyere, 65-69 
Hibler, B. H., tuyere patented by, 63 
Hocking Valley coke, 240 
Holland cupola, 2(i6-2l0 
Homestead large cupolas, 156, 157 
Hoods, cupola, 385. 386 
Horizontal and vertical slot tuyere, 51 
Horse manure for bods, 118 
Hot-blast, 18, 19 

cupolas, 202-214 
theory of obtaining, 210 

IMPROVEMENTS in cupolas, 8-21 
1 Ireland's center blast cupola, 346- 
348 
cupola, 344-346 
double row of tuyeres, 57 
Iron, accurate determination of the 
resultant qualities of an, 165 
action of. at the spout, 85 

tin on, 276, 277 
additional, charging of, 106 
and coke, rule of charging, 247, 

248 
appearance of, at the tap hole, 

109 
boiling of, 84 
charging of, 100, 101 
chilling of, in the tap hole, 94 
cleaning of, by boiling, 270, '.'71 
cold, wet or rusted, explosion of 
molten iron caused by, 303, 304 
cost of melting, 390 
crates for removing dump, 124 
effect of carbon on, 268 
flux upon, 261 
silicon on, 267, 268 
experiments in melting, with gas 

and liquid fuels, 226-228 
flow of, after blast is put on, 119 



Iron, flow of. from tap hole, 1 12 
fluxing of in a cupola, 258-271 
foundries Buffalo blower for cu- 
pola furnaces in, 437, 438 
fuel required for melting, 1 
hot, and climate, 223 

production of, 282 
hotter, in winter, 215 
in slag, 261 

malleable, experiments in mak- 
ing, 266 
melting large pieces of, 273, 274 
of, in a cupola, different 
terms used to indicate, 387 
molten, explosion of, 302-307 
handling of, 389. 39(t 
holding of. in cupola, 111 
per cent, of coke, to, 250 

lost in melting, 266, 
267 
poling of, 270, 271 
preventing the, from running 

into tuyeres, 125 
size of coal of, for melting, 235 
space in which melted, 98 
sparks thrown off by, 3(l3 
time for charging the, before 

putting on blast, l(i9-lll 
tuyeres to improve the quality 

of, 71 
uneven melting of, 102 
use of charcoal (or smelting, 228 
weight of first charge of, 102, 103 
Irons, first step in mixing, 104 

TAGCER, Treadwell & Perry, hot 
J blast cupolas constructed by, 202- 

205 
Johnson, John D., & Co., trouble with 

the cupola of, 262 
Jumbo cupola, 371-374 

KEEP, J. W., investigation by, as 
to the number of cupola men 
required, 323-325 
sectional cupola, 171-173 
Knoeppel, Mr., on banking a cupola, 
286-288 
tuyere, 75, 76 

LADLE, damp, explosion of iron 
caused by, 307 
tapping, 321, 322 
Ladles, filling of, at the spout, 446 

transporiation of, 446 
Large cupolas. 15H-163 

advantages and disadvan- 
tages of, 161-163 



1 



INDEX. 



455 



Lawrence cupola, 16, 17 

reducing tuvere, 53, 54 
Lead, melting of, in a cupola, 272 
Lebanon Stove Works, daily report 

of foundry department of, 294 
Lehigh coal, 231 
Lifting magnets, 311-313 
Lighting up, 95-97 

new method of, 97, 98 
Limestone, amount required to pro- 
duce fluid slag, 260 
as a cupola flux, 259 
impurities in, 2(il, 262 
in large quantities for fluxmg, 

259-261 
use of, in the production of pig 
iron, 258, 259 
Lining, 37-39 

absorption of moisture into, 41 

action of fluxes on, 261-264 

brick for, 134, 135 

common red bnck, 335, 336 

drying the, 77, 78 

efi'ect of fluor spar on, 269 

greatest wear of, 133 

materials for, 6 

mica schist, 334, 335 

object of applying daubing to, 

128, 129 
of casing, 6, 7 
out of shape, examples of, 181- 

189 
renewing a, 334 
shaping the. 128-133 
thickness of, 6, 7 
Linings, new, 129 
Liquid and gas fuel, 225-228 
Loam s mds for bottom, 81 
Lobdell Car Wheel Co., cross spout 
used by, 316- 
318 
experiments to 
produce a 
moist blast 
at, 216, 217 

McSHANE large cupola, 157-159 
Mackenzie cupola, 14, 15, 357- 
361 
tuyere, 49, 50 
Machine and jobbing foundry cupo- 
las, tuyeres in, 68 
Magee Furnace Co., tuyere used by, 

54 
Magnets, lifting, 311-313 
Malleable iron, experiments in mak- 
ing, 266 



Marble spalls, use of. as flux, 265, 266 
Melter, give the, a chance, 288-290 
protecting the, when chip^jiug 
out. 329, 330 
Melting, 108-112 
art in, 280 290 

bad, caused by wood and coal, 
198, 199 
examples of, 181-201 
best practical results for, for gen- 
eral foundry work, 391 
blast in, 4(i8-4l3 
brass in a cupola, 279 
cost of, 298-:;01 
fast, cupola for, 281 . 282 
in old cupolas, theory of, 410 
iron, cost of, 390 
large pieces of iron, 273, 274 
of iron in a cupola, different 

terms used to indicate, 387 
per cent of iron lost in, 266, 267 
point, 98 

to find the, 99 
poor, cause of, 106, 107 

in a Ciucinnaii cupola, 199- 

201 

long blast-pipes cause of, 402 

report from foundries showing 

per cent, of coal consumed in, 

234 

reports of, with Connellsville 

coke, 25() 
space theory of, 246 
tin-plate scr^ip, co^t of, 390 

in a cupola, 275-279 
trouble in, lOO 
with charcoal, 229, 230 

poor coke, 247 
zone, 98 

burning away of lining at, 
134 
Men, number of, required to man a 

cupola, 323-336 
Mercury gauge, -106 
Mica schist lining, 334, 335 
Modern cupolas, 137-155 
Moist or dry cupola blast, 222, 223 
Moisture, air capacity for, 217, 218 
in blast. 216, 217 
temperature of, 221 
Moldenke, Doctor, on small charges 

for a cupola, 327 
Molten metal, explosion of, 83, 84 
Moor's patent cupola breast and.run- 
ner, 336 • i 

Mud, explosion of molten iron'when 
poured into, 305 



456 



INDEX. 



^I EW tuyeres, 72-76 
t Newteu cupola, 141-144 
North Bros., explosion at the foundry 

of, 8(»o, 3(>6 
Number of tuyeres, 69, 70 

OIL in cupola practice, 2^9, 210 
O'Ketfe, John, return flue spark- 
catcher designed by, 882-384 
Old Mine Lehigh coal. 231 
Oliphant, F. H., early production of 

coke by, 238 
Osborne Mower and Reaper Co., 
double spout at the plant of, 315, 
316 
Oval tuyere, 47 
Oyster shells, use of, as flux, 265 

PARIS, Daniel E., & Co., trouble 
with cupolas in the works of, 
19(1-195 
Parting sand, 81 
Patterns, casting of, 166 
Paxson CoUiau cupola, 144-148 
reservoir spout ladle, 320, 321 
truck and track cupola, 176, 177 
Pennsylvania, anthracite coal mines 
in, 23(', 231 
Diamond Drill and Manufactur- 
ing Co., cupola of, 60, 61 
Terry & Co., trouble with cupolas in 

the works of, 181-189 
P^vie cupola, 17, 363-365 
Picks for chipping out, 126 
Pig bed, 330, 331 

iron and old scrap, charging of, 
106 
scrap, mixing of, 105 
charging of, 103 
melting of, in the manufac- 
ture of Bessemer 
steel, 272 
with re-melt scrap, 
105 
of different grades, charging 

of, 105 
use of limestone in the pro- 
duction of, 258, 259 
moulds, iron, 330 
Piqua positive blowers, 428 
Pit beneath cupola, 3 
Pitch of sand bottom, 84, 85 
Poking the tuyeres, 112, 113 
Poling iron. 27'o, 271 
Portable small cupola, 168-170 
Pot furnare. fuel required for, 1 
Prop, device for removing, 80 
foundation for, 79 



Prop, wooden, superstition attached 

to. 80 
Providence Locomotive Works, visit 

to the plant of, U)b-I98 
Putting up the doors, 78-80 

RAMP, Herbert M., on a wonder- 
ful cupola, 251, 255 
Ramson & Co., hot-blast cupola at 

the stove foundry of, 209 
Reeder, Chas., & Sons, cupolas in 

the foundry plant of, 9, 10 
Relining and repairing, 133-136 
Re melt scrap, melting pig iron with, 

105 
Renewing a lining, 334 
Reservoir cupola, 342 

spout ladle, 3l0, 321 
Return flue cupola spark-catcher, 

382-384 
Reverberatory furnace, fuel required 

for, 1 
Reversed T tuyere, 52 
Ridgway & Son Co., elevators made 

by, 310, 311 
Root's rotary pressure blowers, 422- 

424 
Round tuyere, 46 
Running a continuous stream, 315- 

322 
Runways, 308, 309 

SAND bottom, 81-86 
cutting through of, 84 
leakage of, 83-86 
making the, 83 
pitch or slope of, 84, 85 
starting the, 122 
mould, wet, explosion of molten 
iron when poured into, 304, 305 
Sash vi-eighis, 276 
Scafi'old, 7, 22, 23 

location of, 41, 42 
oldest way of placing stock upon 
the, 3t 8 
ScaffoMs, fire-proof, 41-44 
Schuylkill coal, 231 
Scientifically designed cupolas, 337- 

378 
Scrap and pig iron, mixing of, 105 
carrying of, by means of tram- 
rail, 444 
old, and pig iron, charging of, 106 
sheet iron, melting of, 277 
wet, rusted, explosion of molten 
iron when brought in contact 
with, 3n5 
Sectional cupola. Keep, 171-173 



INDEX. 



457 



Setni-steel mixture, 165 
Seveuty-two hour coke, 244, 245 
Shape of tuyeres, 7U, 71 
Shapes of cupolas, 2 
Shapiag the lining, 128-133 
Sharp sand, 81 
Shavings for lighting up, 95 
Sheet blast tuyere, 49 

-iron blast pipes, 395 

scrap, melting of, 277 
Shells, use of, as flux, 265 
Shot iron in slag, 261 
Silicon, effect of, on iron, 267, 268 
Size of tuyeres, 64, 65 
Sizes of cupolas, 2 

Skinner Engine Co., explosion at, 306 
Slag, boiling or foaming, 331 

chilling of. 94 

constitution of, 261 

fluid, amount of limestone re- 
quired to produce, 260 

hole, 33, 93, 94, 263, 264 
front. 94 

iron in, 261 

removal of, from the spout, 89 

tapping of, 19, 107 

tendency of, 259, 260 

weight of, drawn from a cupola, 
260, 261 
Slagging, cost of, 264, 265 

trouble in, 263, 264 
Slope of sand bottom, 84, 85 
Small cupola, value of. as a money 
maker or saver, 164, 165 

cupolas, 164-186 

cheap movable, 170, 171 
management of, 171 
of Europe, 178-180 
Soapstone for daubing, 127 
Sol way coke, 251, 252 
Southern R. R. Co., cupola for re- 
melting alloys in shops of, 279 
Space theory of melting, 246 
Spangler, Chas., cupola in the foun- 

drv of, 166-168 
Spark arrester, 379-382 

catching devices for cupolas, 379- 
393 
Split brick, 135 
Spout, 32, 33, 86-90 

action of iron at the, 85 

basin, 316 

bottom of, 89 

cross, 316-318 

cutting out of, 89 

double, 315, 316 

filling ladles at the, 446 

greatest strain upon, 88, 89 



Spout ladle, 318-320 

reservoir, 320, 321 
lining, cause of cutting out of, 
387 
drying the, 91 
making up the, 87, 88 
materials for, 86 
tilting, 446 

wet, explosion of iron caused by, 
302 
Spouts, modern, 86 
Stack, 5 

casing, 27-29 
lining, 39 
Standard Colliau cupola furnace, 138- 

141 
Stationary bottom cupola, 174, 175 
Stave cupola, old style, 338-341 
Steam, adding of, to blast, 222, 223 
experiments with, to produce a 

moist blast, 216, 217 
-hydraulic elevator, 310, 311 
-jet cupola. Woodward's, 350-354 
cupolas, 369-371 
Steel bar for cutting away the bod, 116 
pressure blowers, 429, 430 

on adjustable bed 
with combined up- 
right engine, 430, 
431 
spring gauge, 406 
Stewart's cupola, 365-367 
Stock, oldest way of placing the, upon 
the scaffold, 3(i8 
yards, elevated, 313, 314 
Stopping in, 120, 121 
Storage yard, tramrail over, 442 
Stove foundrieSj breakage in, 268 

investigation as to the num- 
ber of cupola men required 
in, 323-325 
sand used for bottom in, 81, 
82 
-foundry cupolas, tuyeres in, 67, 
68 
use of small cupola in, 165, 
160 
Straight Line Engine Co., scaffold in 

the foundry of, 44 
Straw for lighting up, 95 
Stream, continuous, running a, 315- 

322 
Sturtevant blowers, 428, 429 

high-pressure blowers, 425-428 
Supports for cupolas, 24 
Swivel cupolas, 166-168 
Syracuse Stove Works, melting sheet 
of, 295 



451 



INDEX. 



''PABLE giviug height and size of 
1 doors, 3) 

of diameter and area of blast- 
pipes, 398 
showing necessary increase in 
diameter for different lengths 
of blast-pipes, o9() 
Tacony Iron Works, Colliau hot-blast 

cupola in, 206 
Tank or reservoir cupola, 3o4-357 
Tanks for mixing irons, 356 
Tap bars, support for, 121 
hole, 31, 32 

appearance of iron at the, 109 
closing the, before putting 

on blast, 110, 111 
flow of iron from, 112 
forming the, 90 
making a, 120 

slag chilling in the, 94 
holes, locating the, 92, 93 
sizes of, 92 
Tapping and stopping in, 119-122 
bars, 11. 5, 116 
ladle, 321, 322 
slag 32 
Test castings, 1 6o 
Three rows of tuyeres, 58, 59 
Tilting spout, 446 
Tin, action of, on iron, 276, 277 
blast- pi pes, 395 

-plate scrap, cost of melting, 390 
loss of metal in melting, 

390 
melting of, 27-5-279 
scrap, experiments in melting, 
276 
Torch for lighting up, 97, 98 
Track runways, 3U9 
Tramrail, 442-447 

constitution of, 442, 443 
Treat, C. A., remarks of, 392 
Triangular-shaped tuyere, 41, 54 
Trolley track, 442-44f 
Trucks for removing dump, 124 
Truesdale cupola, 16 

reducing tuyere, 52, 53 
Tuyere area, combined size of, 65 
boxes, 14, 34, 71, 72 
Blakeney, 50, 51 
bottom, 61-64 
center blast, 61-64, 159, 160, 412, 

413 
Chenney, 56 
Colliau, 56 
Doherty. 48, 49 
double, 57, 58 
expanded, 47, 48 



Tuyere, Greiner, 59, 60 

height of, 65-69 

holes, 5 

horizontal and vertical slot, 51 

Knoeppel, 75, 76 

Lawrence reducing, 53, 54 

Mackenzie, 49, 50 

oval, 47 

reversed T, 52 

round, 46 

sheet blast, 49 

triangular, 51, 54 

Truesdale reducing, 52, 53 

water, 54, 55 

Whiting, 56 

Zippier, 75 
Tuyeres, 34-36, 45-76 

adjustable, 12, 60, 61 

combined area of, 34 

connection of blast-pipes with, 
399 
with belt air-cham- 
ber, 401, 402 
blower, 5 

double row of, 19, 20 

height of, above sand bottom, 35 

high, 389 

improvement in, 389 

location of, 12 

new, 72-76 

number of, 34, 69, 70 

placing of, 411, 412 

poking the, 112, 113 

preventing iron from running 
into, 125 

shape of, 70, 71 

size of, 46, 47, 64, 65 

small, 13 

three rows of, 58, -59 

to improve the quality of iron, 71 

two or more rows of, 36, 37 

variation in the height of, 65, 66 

Watt, 73, 74 
j Two-hour cupola, 14, 15 



u 



NITED States, anthracite coal 
mines in, 231 
Navy Yard, Washing- 
ton, D. C, cupola 
for melting alloys 
at, 279 



T 70ISIN'S cupola, 348-350 

WARMING up a cupola, 196-198 
Waste heat, 221 

utilization of, 28 



INDEX. 



459 



Water, adding of, to blast, 222, 223 

gauge, 406 

tuyere, 54, oo 
Watt cupola tuyere, 73, 74 
Weather and the output of the cupola, 

217-222 
West, Thos. D., large cupola, 159-161 

on bottom tuyere, 63 
Wheelbarrow runways, 308, 309 
Whiting cupola, 148-150 

tuyere, 56 



Wire screen charging door, inde- 
structible, 147, 148 
Wood and coal, bad melting caused 
by. 198, 199 
for lighting up, 95 
Wooden blast-pipes, 395 
Woodward's steam-jet cupola, 350- 
354 

y IPPI^ER tuyere, 75 




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BRANNT'S METALLIC ALLOYS. 

Third Edition, Thoroughly Revised and Enlarged. 
PUBLISHED APRIL 17, 1908. 

the: meztallic allovs. 

A Practical Guide for the Manufacture of all Kinds of Alloys, Amalgams, and 

Solders used by Metal- Workers ; together With their Chemical and Physical 

Properties and their Application In the Arts and the Industries ; 

With an Appendix on the Coloring of Alloys and the Recovery of Waste Metals. 

Edited by 'William T. Brannt. 

Illustrated by 45 Engravings. Third Edition, thoroughly Revised and Enlarged. 577 
pages, 8vo. 

4^ Price SS.OO, free of postage to any address in the world. 

CONTENTS.— Chapter I. Introduction. II. Physical and Chemical Relations of the 
Metals. III. Special Properties of ihe Metals. IV. General Properties of Alloys. V. 
Preparation of Alloys in General. VI. Copper Alloys. VII. Copper-Tin Alloys. VIII. 
Alloys of Copper with Other Metals. IX. Tin Alloys. X. Nickel Alloys. XI. Aluminium 
Allovs. XII. Lead Alloys. XIII. Cadmium /Mloys XIV. Bismuth Alloys. XV. Iron 
Alloys (Alloy Steels). XVI. Silver Alloys XVII. Gold Alloys. XVIII. Alloys of Plat- 
inum and Platinum Metals. XIX. Alloys of Mercury and Other Metals, or Amalgams, 
XX Miscellaneous Alloys. XXI. Soldeis and Soldefmg. XXII. Determination of the 
Constituents of Metallic Alloys, of the Impuriti s of the Technically Most Important 
Metals, etc. Appendix.— Coloring of Alloys. Recovery of Waste Metals. 

4®^ An illustrated circular of 6 pages quarto, giving the full Table of Contents of this im- 
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4®= The above or any of our books sent by mail, free of postage, at ihe publication price, to 
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HEI^RY CAREY BAIRD & CO., 

INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS, 

810 Walnut St., Pliilartelpliia, Pa., U. S. A. 

WILLIAM SELLERS h CO., Incorp., 

PHILADELPHIA. 

MODERN MACHINE TOOLS. 




Centrifugal Sand Mixing MacHine 

For rapidly, thoroughly and evenly mixing 
all kinds of foundry sand. .'. .'. .". .". .*. 

EFFECTIVE. ECOMOMICJU. 

CRANES, SHAFTING/INJECTORS, ETC. 



O^T-A-XiOO-XJE 

OF 

pmtM and pcienMfic Boolj^ 

PUBLISHED BY 

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INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS. 

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<SF" Any of the Books comprised in this Catalogue will he sent by mail, fre* # 

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isr- Where not otherwise stated, all of the Books in this Catalogue are boniL' 
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AMATEUR MECHANICS' WORKSHOP: 

A treatise containing plain and concise directions for the manipule^ 
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Soldering and Carpentry. By the author of the " Lathe and It* 
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ANDES. — Animal Fats and Oils: 

Their Practical Production, Purification and Uses; their Properties^ 
Falsification and Examination. 62 illustrations. 8vo, . ;?4.oo 

ANDES.— Vegetable Fats and Oils: 

Their Practical Preparation, Purification and Employment; theif 
Properties, Adulteration and Examination. 94 illustrations. 8vOk 

S4.00 

ARLOT.— A Complete Guide for Coach Painters : 

Translated from the French o'" M. Arlot, Coach Painter, fof 
eleven years Foreman of Pairv.<ng to M. Eherler, Coach Maker^ 
Paris. By A. A. Fesquet, Chemist and Engineer. To which in 
added an Appendix, containing Informatioa ^-esoecting the Materiais 
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T HENRY CAREY BAIRD & CO.'S CATALOGUE. 

A.RMENGAUD, AMOROUX, AND JOHNSON.— The Practi- 
cal Draughtsman's Book of Industrial Design, and Ma-* 
chinist's and Engineer's Drawing Companion : 

Forming a Complete Course of Mechanical Engineering and Archi 
tectural Drawing. From the French of M Armengaud the elder, 
Prof, of Design in the Conservatoire of Arts antl Industry, Paris, and 
M.M. Armengaud the younger, and Amcroux, Civil Engineers. Re- 
written and arranged with additional matter and plates, selections from 
and examples of the most useful and generally employed mechanism 
of the day. By WiLLiAM Johnson, Assoc. Inst. C. E. Illustrated 
by fifty folio steel plates, and fifty wood-cuts. A new edition, 410 , 

cloth. ^6.00 

ARMSTRONG. — The Construction and Management of Steam 
Boilers : 
By R. Armstrong, C. E. With an Appendix by Robert Mallet, 
C. E., F. R. S. Seventh Edition. Illustrated, i vol. i2mo. .60 

ARROWSMITH.— The Paper-Hanger's Companion: 

Comprising Tools, Pastes, Preparatory Work ; Selection and Hanging 
of Wall- Papers ; Distemper Painting and Cornice-Tinting ; Stencil 
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Useful Wrinkles and Receipts, By James Arrowsmith. A New, 
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25 engravings, 162 pages. (1905) .... ^I.OO 

i^SHTON.— The Theory and Practice of the Art of Designing 
Fancy Cotton and Woollen Cloths from Sample : 
Giving full instructions for reducing drafts, as well as the methods of 
spooling and making out harness for cross drafts and finding any re- 
quired reed; with calculations and tables of yarn. By Frederic T. 
AsHTON, Designer, West Pittsfield, Mass. With fifty-two illustrations. 
One vol. folio ^5 00 

i^SKINSON— Perfumes and their Preparation: 
A Comprehensive Treatise on Perfumery, containing Complete 
Directions for Making Handkerchief Perfumes, Smelling-Salts, 
Sachets, Fumigating Pastils; Preparations for the Care of the Skin, 
the Mouth, the Hair; Cosmetics, Hair Dyes, and other Toilet 
Articles. By G. W. AsKlNSON. Translated from the German by IsiDOR 
Furst. Revised by Charles Rice. 32 Illustrations. 8vo. $3.00 

CRONGNIART. — Coloring and Decoration of Ceramic Ware. 
8.C. J^2.5o 

BAIRD.— The American Cotton Spinner, anc Manager's and 
Carder's Guide: 
A Practical Treatise on Cotton Spinning ; giving the Dimensions and 
Speed of Machinery, Draught and Twist Calculations, etc.; with 
notices of recent Improvements: together with Rules and Examples 
£or making changes in the sizes and numbers of Roving and Yarn. 
Compiled from the papw of the late Robert H. Baird. i2mo. 

«i 50 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 



BAKER. — Long-Span Railway Bridges : 

Comprising Investigations of the Comparative Theoretical and 
Practical Advantages of the various Adopted or Proposed Type 
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B. Baker. i2mo ^i.oo 

BRAN NT. — A Practical Treatise on Distillation and Rec- 
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Comprising Raw Materials ; Production of Malt, Preparation of 
Mashes and of Yeast ; Fermentation ; Distillation and Rectification 
and Purification of AIcoliol j Preparation of Alcoholic Liquors, 
Liqueurs, Cordials, Bitters, Fruit Essences^ Vinegar, etc. ; Examina- 
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itself; Examination of Mashes before and after Fermentation ; Alco- 
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on the Manufacture of Compressed Yeast and the Examination of 
Alcohol and Alcoholic Liquors for Fusel Oil and other Impurities. 
By William T. Brannt, Editor of " The Techno-Chemical Receipt 
Book." Second Edition. Entirely Rewritten. Illustrated by 105 
engravings. 460 pages, 8vo. (Dec, 1903) . . . $4.00 

BAKR.— A Practical Treatise on the Combustion of Coal : 
Including descriptions of various meclTanical devices for the Eco- 
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liquid or gaseous. 8vo. . . • . . . . $2.50 

B ARR. — A Practical Treatise on High Pressure Steam Boilers: 
Including Results of Recent Experimental Tests of Boiler Materials, 
together with a description of Approved Safety Apparatus, Steam 
Pumps, Injectors and Economizers in actual use. By Wm. M. Barr. 
204 Illustrations. 8vo $3-00 

BAUERMAN. — A Treatise on the Metallurgy of Iron : 

Containing Outlines of the History of Iron Manufacture, Methods of 
Assay, and Analysis of Iron Ores, Processes of Manufacture of Iron 
and Steel, etc., etc. By H. Bauerman, F. G. S., Associate of the 
Royal School of Mines. Fifth Edition, Revised and Enlarged. 
Illustrated with numerous Wood Engravings from Drawings by J. B. 
Jordan. i2mo, ;?2.oq 

BRANNT. — The Metallic Alloys : A Practical Guide 

For the Manufacture of all kinds of Alloys, Amalgams, and Solders, 
used by Metal-Workers : together with their Chemical and Physical 
Properties and their Application in the Arts and the Industries ; with 
an Appendix on the Coloring of Alloys and the Recovery of Waste 
Metals. By William T. Brannt. 45 Engravings. Third, Re- 
vised, and Enlarged Edition. 570 pages. Svo. . Net, jS^S.oo 

BRANNT. — The Soap Maker's Hand-Book of Materials, Processes 
and Receipts for Every Description of Soap. Illustrated. Svo. (In 
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BEANS. — A Treatise on Railway Curves and Location of 
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By E. W. Beans, C. E. Illustrated. i2mo. Tucks. . $1.50 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 



BELL. — Carpentry Made Easy: 

Or, The Science and Art of Framing on a New and ]mpiuve# 
System. With Specific Instructions for Building Balloon Frames, Barr* 
Frames, M.i!l Frames, Warehouses, Church Spires, etc. Compp=;ing 
also a System of Bridge Building, with Btlls, Estimates of Cnst, and 
valuable Tables. Illustrated by forty-four plates, comprising .ncarlv- 
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8vo. .... ..... $5.00- 

6EMROSE. — Fret-Cutting and Perforated Carving: 

With fifty-three practical illusiraiions. By W. Bi.mrusk, Jr. I voU. 
quarto .......... S2.5O 

BEMROSE.— Manual of Buhl-work and Marquetry: 

With Practical Instructions for Learners, and ninety colored design-^ 
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BEMROSE.— Manual of Wood Carving: 

With Practical Illustrations for Learners of the Ar'., ?nd Original ..i.(t 
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BERSCH.— Cellulose, Cellulose Products, and Rubber Sub- 
stitutes : 
Comprising the Freparation of Cellulose, Parchment Cellulose,. 
Methods of Obtainiria Sugar, Alcohol and Oxalic Acid from \^'oo(!- 
Celhilose ; Production of Nitro-Cellulose and Cellulose Esters ; 
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BILLINGS.— Tobacco: 

Its History, Variety, Culture, Manufacture, Commerce, and Various 
Modes of Use. By E. R. Billings. Illustrated by nearly 200 
engravings. 8vo. ........ ^3. 00 

BIRD.— The American Practical Dyers' Companion : 

Comprising a Description of the Principal Dye- Stuffs and Chemical.s- 
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with the best American, English, French and Cerman processes for 
Bleaching and Dyeing .Silk, Wool, Cotton, Linen, Flannel, Fell. 
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Wool, and .Straw Hats, Jute Yarn, Vegetable Ivory, Mats, Skins, 
F'urs, Leather, etc., etc. By Wood Aniline, and other Processes, 
together with Remarks on Finishing Agents, and instructions in the 
Finishing of Fabrics, Substitutes for Indigo, Water-Proofing of 
Materials, Tests and Purification of Water, Manufacture of .\niline 
and other New Dye Wares, Harmonizing Colors, etc., etc. ; embrac- 
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170 Dvfd Samfiics of Ra~v Materials and Fabrics. By F. J. Bird, 
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HENRY CAREY BAIRD & CO.'S CATALOGUE 



BLINN.— A Practical Workshop Companion for Tin, Sheet- 
Iron, and Copperplate Workers: 
Containing Rules 'for describing various kinds of Patterns used by 
Tin, Sheet-Iron and Copper- plate Workers; Practical Geometry; 
Mensuration of Surfaces and Solids ; Tables of the Weights of 
Metals, Lead-pipe, etc. ; Tables of Areas and Circumference! 
of Circles ; Japan, Varnishes, Lackers, Cements, Compi sitions, etc., 
etc. By Leroy J. Blinn, Master Mechanic. With One Hundred 
and Seventy lUubtrations. i2mo ^3.50 

BOOTH. — Marble Worker's Manual: 

Containing I'raciical 1 nlnrniation respecting Marbles in general, theit 
Cutting, Working and Polisliing; Veneering of Marble; Mosaics; 
Composition and Use of Artificial Marble, Stuccos, Cements, Receipts, 
Secrets, etc., etc. Translated from the French by M. L. Booth. 
With an Appendix concerning American Marbles. l2mo., cloth $1.50 

BRANNT.— A Practical Treatise on Animal and Vegetable 

Fats and Oils • 

Comprising both Fixed and Volatile Oils, their Physical and Chem- 
ical Propeities and Uses, the Manner of Extracting and Refining 
them, and Practical Rules for Testing them; as well as the Manufac- 
ture of Artificial Butter and Lubricants, etc., with lists of American 
Patents relating to the Extraction, Rendering, Refining, Decomposing, 
and Bleaching of Fats and Oils. By William T. Brannt, Editor 
of the " Techno Chemical Receipt Book." Second Edition, Revised 
and in a great part Rewritten. Illustrated by 302 Engravings. In 

Two Volumes. 1304 pp. 8vo $10.00 

BRANNT. — A Practical Treatise on the Manufacture of Soap 
and Candles : 
Based upon the most Recent Experiences in the Practice and Science ; 
comprising the Chemistry, Raw Materials, Machinery, and Utensils 
and Various Processes of Manufacture, including a great variety of 
forinulas. Edited chiefly from the German of Dr. C. Deite, A, 
Engelhardt, Dr. C, Schaedler and others; with additions and list? 
of American Patents relating to these subjects. By Wm. T. Brannt. 
Illustrated by 163 engravings. 677 pages. 8vo. . . ^12.50 

BRANNT —India Rubber, Gutta-Percha and Balata : 

Occurrence, Geographical Distribution, and Cultivation, Obtaining 
and Preparing the Raw Materials, Modes of Working and Utilizing 
them, Including Washing, Maceration, Mixing, Vulcanizing, Rubber 
and Gutta-Percha Compounds, Utilization of Waste, etc. By Will- 
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HENRY CAREY BAIRD & CO.'S CATALOGUE. 



BRANNT— WAHL.— The Techno-Chemical Receipt Book : 

Containing several thousand Receipts covering the latest, most im. 
portant, and most useful discoveries in Chemical Technology, and 
their Practical Application in the Arts and the Industries. Edited 
chiefly from the German of Drs. Winckler, Eisner, Heintze, Mier- 
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Brannt and Wm. H. Wahl, Ph. D. Illustrated by 78 engravings. 
l2mo. 495 pages ^2.00 

BROWN. — Five Hundred and Seven Mechanical Movements : 
Embracing all those which are most important in Dynamics, Hy- 
draulics, Hydrostatics, Pneumatics, Steam Engines, Mill and other 
Gearing, Presses, Horology, and Miscellaneous Machinery ; and in- 
cluding many movements never before published, and several of 
which have only recently come into use. By Henry T. Brown. 
l2mo. . . . ' ^I.oo 

BUCKMASTER.— The Elements of Mechanical Physics : 
By J. C. BucKMASTER. Illustrated with numerous engravings. 
l2mo • ^1.00 

9ULLOCK.— The American Cottage Builder : 
A Series of Dosigns, Plans and Specitications, from ^200 to $20,000, 
for Homes for the People; together with Warming, Ventilation, 
Drainage, Painting and Landscape Gardening. By John Bullock, 
Architect and Editor of " The Rudiments of Architecture and 
Building," etc., eic. Illustrated by 75 engravincrs. 8vo. 

BULLOCK. — The Rudiments of Architecture and Building : 
For the use of Architects, Builders, Draughtsmen, Machinists, En- 
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American Cottage Builder." Illustrated by 250 Engravings. Svo. $2.50 

BURGH.— Practical Rules for the Proportions of Modern 
Engines and Boilers for Land and Marine Purposes. 
By N. P. BiJRCH, Engineer. i2mo. .... ^1.50 

BYLES — Sophisms of Free Trade and Popular Political 

Economy Examined. 

By a Barrister (Sir John Barnard Byles, Judge of Common 

Pleas). From the Ninth English Edition, as published by the 

Manchester Reciprocity Associadcn. i2mo. . . . $1.25 

BOWMAN.— The Structure of the Wool Fibre in its Relation 
to the Use of Wool for Technical Purposes: 
Being the substance, with additions, of Five Lectures, delivered at 
the request of the Council, to the members of the Bradford Technical 
College, and the Society of Dyers and Colorists. By F. H. Bow- 
man, D. Sc, V. R. S. E., F. L. S. Illustrated by 32 engravings. 
Svo. . . . ....... .00 

BYRNE.— Hand-Book for the Artisan, Mechanic, and Engi- 

neer : 

Comprising the Grinding and Sharpening of Cutting Tools, Abrasive 

Processes, Lapidary Work, Gem and Glass Engraving, Varnishing 

and Lackering, Apparatus, Materials and Processes for Grinding and 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 



Polishing, etc. By Oliver Byrne. Illustrated by 185 wood en- 
gravings. 8vo. ........ $.5.00 

3YRNE.— Pocket-Book for Railroad and Civil Engineers: 

Containing New, Exact and Concise Methods for Laying out Railroad 
Curves, Switches, Frog Angles and Crossings ; the Staking out of 
work ; Levelling ; the Calculation of Cuttings : Embankments ; Earth- 
work, etc, By Oliver Byrne. i8mo., full bound, pocket-book 
form ;5!l.50 

. BYRNE. —Tne Practical Metal- Worker's Assistant: 

Comprising Metallurgic Chemistry; the Arts of Working all Metal* 
and Alloys; Forging of Lon and Steel; Hardening and Tempering; 
Melting and Mixing; Casting and Founding; Works in Sheet Metal; 
the Processes Dependent on the Ductility of the Metals; Soldering; 
and the most Improved Processes and Tools employed by Metal- 
workers. With the Application of the Art of ElectroMetallurgy to 
Manufacturing Processes; collected from Original Sources, and from 
the works of Holtzapffel, Bergeron, Leupold, Piumier, Napier, 
Scoffern, Clay, Fairbairn and others. By Oliver Byrne. A new, 
revised and improved edition, to which is added an Appendix, con- 
taining The Manufacture of Russian Sheet-Iron. By JoHN PERCY, 
M. D., F. R. S. The Manufacture of Malleable Iron Castings, and 
Improvements in Bessemer Steel. By A. A. Fesquet, Chemist and 
Engineer. With over Six Hundred Engravings, Illustrating every 
Branch of the Subject. 8vo ^5.00 

BYRNE.— The Practical Model Calculator: 

For the Engineer, Mechanic, Manufacturer of Engine Work, Navai 
Architect, Miner and Millwright. By Oliver Byrne. 8vo., nearly 
^00 pages (Scarce.) 

r\T^TNET MAKER'S ALBUM OF FURNITURE i 

Comprising a Collection of Designs for various Styles of Fumitnre. 
Illustrated by Forty-eight Large and Beautifully Engrav-d Plates. 
Ohiong, 8vo ^1.50 

CALLINGHAM. — Sign Writing and Glass Embossing: 

A Complete Practical Illustrated Manual of the Art. By James 
Callingham. To which are added Numerous Alphabets and the 
Art of Letter Painting Made Easy. By James C. Badenoch. 258 

pages. i2mo I1.50 

CAMPIN.— A Practical Treatise on Mechanical Engineering: 
Comprising Metallurgy, Moulding, Casting, Forging, Tools, Work, 
shop Machinery, Mechanical Manipulation, Manufacture of Steam- 
Engines, etc. With an Appendix on the Analysis of Iron and Iron 
Ores. By Fpancis Campin, C. E. To which are added, Observations 
on the Construction of Steam Boilers, and Remarks upon Furnaces 
used for Smoke Prevention ; with a Chapter on Explosions. By R, 
Armstrong, C. E., and John Bourne, (scarce.) 



HENRY CAREY BAIRD & CG/S CATALOGUE. 



CAREY.— A Memoir of Henry C. Carey. 
By Dr. Wm. Elder. With a portrait. 8vo., cloth . . 75 

CXAREY.— The Works of Henry C. Carey : 

Harmony of Interests : Agricultural, Manufacturing and Commer 

cial. 8vo. . . $t.2^' 

Manual of Social Science. Condensed from Carey's '• Principles 
of Social Science." By Kate McKean. i vol. i2mo. . jSa.oo 
Miscellaneous Works. With a Portrait. 2 vols. 8vo. 1 10 00 
Past, Present and Future. Svo. ..... $2.50 

Principles of Social Science. 3 volumes, Svo. . . g 10.00 
The Slave-Trade, Domestic and Foreign; Why it Exists, and 
How it may be Extinguished (1853). ^^o- • • • $2.O0 

The Unity of Law : As Exhibited in the Relations of Physical, 
Social, Mental and Moral Science (1872). Svo. . , $2.50 

CLARK. — Tramways, their Construction and Working : 

Embracing a Comprehensive History of the System. With an ex- 
haustive analysis of the various modes of traction, including horse- 
power, steam, heated water and compressed air; a description of the 
varieties of Rolling stock, and ample details of cost and working ex- 
penses. By D. KiNNEAR Clark. Illustrated by over 200 wood 
engravings, and thirteen folding plates. I vol. 8vo. . $S-00 

COLBURN.— The Locomotive Engine : 

Including a Description of its Structure, Rules for Estimating its 
Capabilities, and Practical Observations on its Construction and Man 
agement. By Zerah Colburn. Illustrated. i2mo. . $1.00 

rOLLENS.— The Eden of Labor ; or, the Christian Utopia. 
By T. Wharton Collens, author of " Humanics," " The Historj 
of Charity," etc. l2mo. Paper cover, $1.00; Cloth . ^1.25 

COOLEY. — A Complete Practical Treatise on Perfumery : 
Being a Hand-book of Perfumes, Cosmetics and other Toilet Article! 
With a Comprehensive Collection of Formulae. By ARNOLD j 
CooLEY. i2mo ^1.50 

COOPER.— A Treatise on the use of Belting for t^e Trant- 
mission of Power. 
With numerous illustrations of approved and actual methods of ar- 
ranging Main Driving and Quarter Twist Belts, and of Belt Fasten 
ings. Examples and Rules in great number for exhibiting and cal- 
culating the size and driving power of Bells. Plain, Particular and 
Practical Directions for the Treatment, Care and Management o'^ 
Belts. Descriptions of many varieties of Beltings, together with 
chapters on the Transmission of Power by Ropes ; by Iron and 
Wood Frictional Gearing; on the Strength of Belting Leather; and 
on the Experimental Investigations of Morin, Briggs, and others. By 
John H. Cooper, M. E. Svo iS^S'SO 

CRAIK. — The Practical American Millwright and M^ler. 

By David Craik, Millwright. Illustrated by numerous wooa en 
gravings and two folding plates. Svo. . . , ■ (Scarce.1 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 



CROSS.— The Cotton Yarn Spinner: 

Showing how the Preparation should be arninged for Differeni 
Counts of Yarns by a System more uniform than has hitherto been 
practiced; by having a Standard Schedule from which we make ail 
our Changes. By Richard Cross. 122 pp. lamo. . 75 

CRISTIANI.— A Technical Treatise on Soap and Candles: 

With a Glance at the Industry of Fats and Oils. By R. S. Cris- 
TiANi, Chemist. Author of " Perfumery and Kindred Arts." Illus- 
trated by 176 engravings. 581 pages, 8vo. ^iq.oo 

COURTNEY.— The Boiler Maker's Assistant in Drawing, 
Templating, and Calculating Boiler Work and Tank 
Work, etc. 
Revised by D. K. Clark. 102 ills. Fifth edition. . . 80 
COURTNEY.— The Boiler Maker's Ready Reckoner: 

With Examples of Practical Geometry and Templating. Revised by 
D. K. Clark, C. E. 37 illustrations. Fifth edition. . ji5l.60 

DAVIDSON.— A Practical Manual of House Painting, Grain- 
ing, Marbling, and Sign- Writing: 
Containing full information on the processes of House Painting in 
Oil and Distemper, the Formation of Letters and Practice of Sign- 
Writing, the Principles of Decorative Art, a Course of Elementary 
Drawing for House Painters, Writers, etc., and a Collection of Useful 
Receipts. With nine colored illustrations of Woods and Marbles, 
- and numerous wood engravings. By Ellis A. Davidson. i2mo. 

^2.00 

DAVIES.— A Treatise on Earthy and Other Minerals and 
Mining: 
By D. C. Davies, F. G. S., Mining Engineer, etc. Illustrated by 
76 Engravings. i2mo. IS5.00 

DAVIES. — A Treatise on Metalliferous Minerals and Mining: 
By D. C. Davies, F. G. S , Mining Engineer, Examiner of Mines, 
Quarries and Collieries. Illustrated by 148 engravings of Geological 
Formations, Mining Operations and Machinery, drawn from the 
practice of all parts of the world. Fifth Edition, thoroughly Revised 
and much Enlarged by his son, E. Henry Davies. l2mo., 524 
pages . . ;5!5.oo 

DIETERICHS.— A Treatise on Friction, Lubrication, Oils 
and Fats : 
The Manufacture of Lubricating Oils, Paint Oils, and of Grease, and 
the Testing of Oils. By E. F. Dieterichs, Member of the Franklin 
Institute; Member National Association of Stationary Engineers; 
Inventorof Dieterichs' Valve-Oleum Lubricating Oils. i2mo, (1906.) 
A practical book by a practical 9)ian. .... $1.2^ 

DAVIS. — A Practical Treatise on the Manufacture of Brick, 

Tiles and Terra-Cotta : 

Including Stiff Clay, Dry Clay, Hand Made, Pressed or Front, and 

Roadway Paving Brick, Enamelled Brick, with Glazes and CoUw, 

Fire Brick and Blocks. Silica Brick, Carbon Brick, Glass Pots, %*■ 



lo HENRY CAREY BAIRD & CO.'S CATALOGlJt>. 

torts, Architectural Terra-Cotta, Sewer Pipe, Drain Tile, Glazed and 
Unglazed Roofing Tile, Art Tile, Mosaics, and Imitation of Intar.sia 
or Inlaid Surfaces. Comprising every product of Clay employed in 
Architecture, Engineering, and the Blast Furnace. With a Detailed 
Description of tlie Different Clays employed, the Most Modern 
Machinery, Tools, and Kilns used, and the Processes for Handling, 
Disintegrating, Tempering, and Moulding the Clay into Shape, Dry- 
ing, Setting, and Burning. By Charles Thomas Davis. Third Edi- 
tion. Revised and in great part rewritten. Illu.'-trated by 261 
engravings. 662 pages ....... ^20.00 

DAVIS. — A Treatise on Steam-Boiler Incrustation and Meth- 
ods for Preventing Corrosion and the Formation of Scale: 
By Charles T. Davis. Illustrated by 65 engravings. 8vo. 
DAVIS. — The Manufacture of Paper: 

Being a Description of the various Processes for the Fabrication, 
('oloring and Finishing of every kind of Paper, Including the Dif- 
ferent Raw Materials and the Methods for Determining their Values, 
the Tools, Machines and Practical Details connected with an intelli- 
gent and a piolitable prosecution of the art, with special reference to 
the best American Practice. To which are added a History of Pa- 
per, complete Lists of Paper-Making Materials, List of Anu-rican 
Machines, Tools and Processes used in treating the Raw Materials, 
and in Making, Coloring and Finishing Paper. By Charles T. 
Davis. Illustrated by 156 engravings. 608 pages, Svo. ;^6.oo 

DAVIS. — The Manufacture of Leather: 

Being a Description of all the Processes for the Tanning and Tawing 
with Bark, Extracts, Chrome and all Modern Tannages in General 
Use, and the Currying, Finishing and Dyeing of Every Kinii of Leaiher; 
Including the Various Raw Materials, the Tools, Machines, and all 
Details of Importance Connected with an Intellit;ent and Pioiiiable 
Prosecution of the Art, with Special Reference to the Best American 
Practice. To which aie added Lists of American Patents ( 1884-1897) 
for Materials, Processes, Tools and Machines for Tanning, Currying, 
etc. By Charles Thomas Davis. Second Edition, Revised, and 
in great part Rewritten. Illustrated by 147 engravings and 14 Sam- 
ples of Quebracho Tanned and Aniline Dyed Leathers. Svo, cloth, 

712 pages. Price $12.50 

DAWIDOWSKY— BRANNT.— A Practical Treatise on the 

Raw Materials and Fabrication of Glue, Gelatine, Gelatine 

Veneers and Foils, Isinglass, Cements, Pastes, Mucilages, 

etc. : 

Eased upon Actual Experience. By F. Dawidowsky, Technical 

Chemist. Translated from the German, with extensive additions, 

including a description of the most Recent American Processes, hy 

William T. Brannt. 2d revised edition, 350 pages. (1905.) 

Price Jlj.oo 

DE GRAFF.— The Geometrical Stair-Builders' Guide: 

being a Plain Practical System of Hand-Railing, embracing all ita 
necessary Details, and Geometrically Illustrated by twenty-tw.o Stee! 
Engravings; together with the use of tlie most approved pnnciple. 
nf Practical Geometry By Simon De Graff. Architeict (Scan... j 



HENRY CAREY BAIRD & CO.'S CATALOGUE. l\ 

DE KONINCK— DIETZ.— A Practical Manual of Chemical 
Analysis and Assaying : 

As applied to the Manufacture of Iron from its Ores, and to Cast Iron, 
Wrought Iron, and Steel, as found in Commerce. By L. L. Dh 
KoNlNCK, Dr. Sc, and E. Dietz, Engineer. Edited with Notes, by 
Robert Mallet, F. R. S., F. S. G., M. I. C. E., etc. America^ 
Edition, Edited with Notes and an Appendix on Iron Ores, by A. A. 
Fesquet, Chemist and Engineer. lamo. . . . ;^i.oo 

DUNCAN.— Practical Surveyor's Guide: 
Containing the necessary information to make any person of com) 
mon capacity, a finished land surveyor without the aid of a teacher. 
By Andrew Duncan. Revised. 72 engravings, 214pp. i2mo. $i.So 

DUPLAIS. — A Treatise on the Manufacture and Distillation 
of Alcoholic Liquors : 
Comprising Accurate and Complete Details in Regard to Alcohol 
from Wine, Molasses, Beets, Grain, Rice, Potatoes, Sorghum, Aspho 
del. Fruits, etc.; with the Distillation and Rectification of Brandy 
Whiskey, Rum, Gin, Swiss Absinthe, etc., the Preparation of Aro- 
matic Waters, Volatile Oils or Essences, Sugars, Syrups, Aromatic 
Tinctures, Liqueurs, Cordial Wines, Effervescing Wines, etc., tlw 
Ageing of Brandy and the improvement of Spirits, with Copious 
Directions and Tables for Testing and Reducing Sjiirituous Liquors, 
etc>« etc. Translated and Edited from the French of MM. DuPI.AIS, 
By M. McKennie, M. D. Illustrated 743 pp. 8vo. $15.00 

OYER AND COLOR-MAKER'S COM PANION : 

Containing upwards of two hundred Receipts for making Colors, OQ 
the most approved principles, for all the various styles and fabrics novf 
in evi.stence ; with the Scouring Process, and plain Directions for 
Preparing, Washing-oft', and Finisliing the Goods. i2mo. $1 OO 

EIDHERR. — The Techno-Chemical Guide to Distillation: 
A Hand-Book for the Manufacture of Alcohul ami Alcoholic Liquors, 
including the Preparation of Malt and Compressed Yeast. Edited 
from tiie German of Ed. Eidherr. 

EDWARDS. — A Catechism of the Marine Steam-Engine, 
For the use of Engineers, Firemen, and Mechanics. A Practical 
Work for Practic.nl Men. By Emory Edwards, Mechanical Engi- 
neer. Illustrated by sixty-three Engravings, including examples of 
the most modern Engines. Third edition, thoroughly revised, with 
much addition.il mattfr. I2mo. 414 jiages . . $2 OO 

SDWARDS. — Modern American Locomotive Engines, 
Their Design, Construction and Management. By Emory EdwarDS. 
Illustrated i2mo $2.00 

EDWARDS.— The American Steam Engineer: 

Theoretical and Practical, with examples of the late^-. and most ap- 
proved American practice in the design and construction of Steam 
Engipes and Boilers. For the use of engineers, machinists, boiler- 
t»»'<kers, and engineering students. By Emory Edward6. Fully 
Ulustrated, 419 pages. i2mo. ■ . , . |2.oo 



12 HENRY CAREY BAIRD & CO.'S CATALOGUE. 

EDWARDS. — Modern American Marine Engines, Boilers, aiM 

Screw Propellers, 
Their Design and Construction. Showing the Present Practice ot 
the most Eminent Engineers and Marine Engine Builders in the 
United States. Illustrated by 30 large and elaborate plates. 4to. ^3.00 

EDWARDS.— The Practical Steam Engineer's Guide 

In the Design, Construction, and Management of American Stationary, 
Portable, and Steam Fire- Engines, Steam Pumps, Boilers, Injector^ 
Governors, Indicators, Pistons and Rings, Safety Valves and Steam 
Gauges. For the use of Engineers, Firemen, and Steam Users. By 
E^ORY Edwards. Illustrated by 119 engravings. 4.20 pages. 
l2mo ^2.00 

EISSLER.— The Metallurgy of Silver : 

A Practical Treatise on the Amalgamation, Roasting, and Lixivi-ation 
of Silver Ores, including the Assaying, Melting, and Refining of 
Silver Bullion. By M. Eissler. 124 Illustrations. 336 pp. 
i2mo. .......... $-i-2^ 

ELDER. — Conversations on the Principal Subjects of Political 
Economy. 
By Dr. William Elder. 8vo. ... , ;JS2.oo 

ELDER. — Questions of the Day, 

Economic and Social. By Dr. William Elder. 8vo, . $3.00 

ERNI AND BROWN.— Mineralogy Simplified. 

Easy Methods of Identifying Minerals, including Ores, by Means of 
the Blow-pipe, by Flame Reactions, by Humid Chemical Analysis, 
and by Physicaf Tests. By Henri Erni, A. M., M. D. Fourth Edi- 
tion, revised, re-arranged and with the addition of entirely new matter, 
including Tables for the Determination of Minerals by Chemical and 
Pyrognostic Characters, and by Physical Characters. By Amos P. 
Brown, E. M., Ph. D. 464pp..illustrateilby 123 engravings, pocket- 
book form, full flexible morocco, gilt edges . . . ^2.50 

FAIRBAIRN. The Principles of Mechanism and Machinery 
of Transmission : 
Comprising the Principles of Mechanism, Wheels, and Pulleys, 
Strength and Proportion of Shafts, Coupling of Shafts, and Engag- 
ing and Disengaging Gear. By Sir William Fairbairn, Bart. 
C. E. Beautifully illustrated by over 150 wood-cuts. In one 
volume, i2mo. . . ... . . . ;}i2.oo 

FLEMING.— Narrow Gauge Railways in America : 

A Sketch of their Rise, Progress, and Success. Valuable Statistics 
as to Grades,. Curves, Weight of Rail, Locomotives, Cars, etc. By 
Howard Fleming. Illustrated, Svo ^i.oo 

FORSYTH.— Book of Designs for Headstones, Mural, and 
other Monuments : 
Containing 78 Designs. By James Forsyth, With an Introduction 
by Charles Boutell, M. A. 410., cloth . . . ^^3.50 

FRIEDBERG. Utilization of Bones by Chemical Means; 
especially the Modes of Obtaining Fat, Glue, Manures, 
Phosphorus and Phosphates. 
Illustrated. 8vo. (In preparation. ) 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 13 



t RANKEL— HUTTER.— A Practical Treatise on the Manu. 
facture of Starch, Glucose, Starch-Sugar, and Dextrine: 

Based on the German of Ladislaus Von Wagner, Professor in the 
Royal Technical High School, BudaPest, Hungary, and other 
authorities. By Julius Frankel, Graduate of the Polytechnic 
School of Hanover. Edited by Robert Hutter, Chemist, Practical 
Manufacturer of Starch-Sugar. Illustrated by 58 engravings, cover- 
ing every branch of the subject, including examples of the most 
, Recent and Best American Machinery. 8vo., 344 op. «6 00 

ijARDNER.— The Painter's Encyclopaedia: 

Containing Definitions of a',1 Important Words in the Art of Plain 
and Artistic Painting, with Details of Practice in Coach, Carriage 
Railway Car, House, Sign, and Ornamental Painting, including 
Grainmg, Marbling, Staining. Varnishing, Polishing, Lettering 
Stenciling, Gilding, Bronzing, etc. By Franklin B.' Gardner! 
158 Illustrations. i2mo. 427 pp. . . . , _ ^2 OC 

GARDNER. — Everybody's Paint Book : 

A Complete Guiile to the Art of Outdoor and Indooi Painting. 38 
illustrations. i2mo, 183 pp ^I.oo 

GEE. — The Jeweller's Assistant in the Art of Working in 
Gold: 
A Practical Treatise foi Masters and Workmen, i2mo. . ^3.00 
GEE.— The Goldsmith's Handbook : 

Containing full instructions for the Alloying and Working of Gold, 
including the Art of Alloying, Melting, Reducing, Coloring, Col 
lecting, and Refining; the Processes of Manipulation, Recovery of 
Waste; Chemical and Physical Properties of Gold; with a New 
System of Mixing its Alloys ; Solders, Enamels, and other Useful 
Rules and Recipes. By George E. Gee. i2mo. ., . ^jSi.a? 

GEE.— The Silversmith's Handbook : 

Containing full instructions for the Alloying and Working of Silver, 
including the different modes of Refinir-; :.nd Melting the Metal; its 
Solders; the Preparation of Imitation Alloys; Methods of Manipula- 
tion ; Prevention of Waste ; Instructions for Improving and Finishing 
the Surface of the Work ; together with other Useful Information and 
Memoranda. By George E. Gee. Illustrated. l2mo. Si. 25 

GOTHIC ALBUM FOR CABINET-MAKERS: 

Designs for Gothic Furniture. Twenty-three plates. Oblong ^1.50 

GRANT.— A Handbook on the Teeth of Gears : 
Their Curves, Properties, and Practical Construction. By George 
B. Grant. Illustrated. Third Edition, enlarged. Svo. ^100 

GREENWOOD,— Iron and Steel: 

Vol. I. Iron : Its Sources, Properties, and Manufacture. By Will- 
iam Henry Greenwood. Revised and Re-written by A. Hum- 
boldt Sexton. 255pp. Illustrated i2mo. . . . ;$i.oo 
Vol.11. Steel- Its Varieties, Properties, and Manufacture By 
William Henry Greenwood. Revised and Re-written by A. 
HuMiiOLDT Sexton. 254pp. Illustrated. i2mo. . . $1.00 



14 HENRY CAREY BAIRD & CO.'S CATALOGUE 



GREGORY.— Mathematics for Practical Men : 

Adapted to the Pursuits of Surveyors, Architects, Mechanics, and 
CivU Engineers. By Olinthus Gregory. 8vo., plates $3-0(i 
GRISWOLD. — Railroad Engineer's Pocket Companion for thk 
Field : 
Comprising Rules for Calculating Deflection Distances and Angles, 
Tangential Distances and Angles, and all Necessary Tables for En 
gineers; also the Art of Levelling from Pie'liminary Survey to the 
Construction of Railroads, intended Expressly for the Young Er>- 
gineer, together with Numerous Valuable Rules and Examples. By 

W. Griswold. i2mo., tucks ' $1.50 

ORUNER. — Studies of Blast Furnace Phenomena: 

By M. L. Gruner, President of the General Council of Mines o" 
France, and lately Professor of Metallurgy at the Ecole des Mine-. 
Translated, with the author's sanction, with an appendix, by L. D 
B. Gordon, F. R. S. E., F. G. S. 8vo. . . . ^2. 50 

Hand-Book of Useful Tabl«s for the Lumberman, Farmet and 
Mechanic: 

Containing Accurate Tables of Logs Reduced to Inch Board Meas- 
ure, Plank, Scantling and Timber Measure; Wages and Rent, by 
Week or Month; Capacity of Granaries, Bins and Cisterns; Land 
Measure, Interest Tables, with Directions for Finding the Interest on 
any sum at 4, 5, 6, 7 and 8 per cent., and many other Useful Tables 
32 mo., boards. lS6 pages ...... .25 

HASERICK.— The Secrets of the Art of Dyeing Wool, Cotton 
and Linen, 
Including Bleach'irg and Coloring Wool and Cotton Hosiery and 
Random Yarns. A Treatise based on Economy and Practice. B^' 
E. C. Haserick. Illustrated by 323 Dyed Patterns of the Yarm 
or Fabrics. 8"o. ........ j?5.00 

HATS AND FELTING: 

A Practical Treatise on their Manufacture. By a Practical Hatter, 
Illustrated by Drawings of Machinery, etc. 8vo. . . ^i.oo 

HERMANN. — Painting oh Glass and Porcelain, and Enamel 
Painting: 
A Complete Introduction to the Preparation of all the Colors and 
Fluxes Used for Painting on Glass, Porcelain, Enamel, Faience and 
Stoneware, the Color Pastes and Colored Glasses, together with t 
Minute Description ol the Firing ot Colors and Enamels, on th« 
Basis of Personal Practical Experience of the Art up to Date. 18 
illustrations. Second edition. ..... #4.00 

HAUPT. — Street Railway Motors: 

With Descriptions and Cost of Plants and Operation of the Various 
Systems now in Use. isr"* , . . . lS!i-75 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 15 

HAUPT. — A Manual of Engineering Specifications and Con* 
tracts. 
By Lewis M. Haupt, C. E. Illustrated with numerous maps. 

328pp. 8vo ;83 00 

HAUPT. — The Topographer, His Instruments and Methods. 
By Lewis M. Haupt, A. M., C. E. Illustrated with numerous 
plates, maps and engravings. 247 pp. 8vo. . . . ^3-00 
HUGHES. — American Miller and Millwright's Assistant: 

By William Carter Hughes. i2mo ^1.50 

HULME. — Worked Examination Questions in Plane Gecrnet • 
rical Drawing : 
For the Use of Candidates for the Royal Military Academy, Wool- 
wich; the Royal Military College, Sandhurst ; the Indian Civil En- 
gineering College, Cooper's Hill ; Indian Public Works and Tele- 
graph Departments; Royal Marine Light Infantry; the Oxford and 
Cambridge Local Examinations, etc. By F. Edward Hulme, F. L. 
S., F. S. A., Art-Master Marlborough College. Illustrated by 300 
examples. Small quarto . . . . . - Si 00 

JEK VIS. —Railroad Property: 

A Treatise on the Construction and Management of Railways; 
designed to afford useful knowledge, in the popular style, to tha 
holders of this class of property ; as well as Railway Managers, fjffi. 
cers, ar.d Agents. By JOHN B. Jervis, late Civil Engineer of the 
Hudson River Railroad, Croton Aqueduct, etc. i2mo., cloth $i.f;o 
KEENE.— A Hand-Book of Practical Gauging: 

For the Use of Beginners, to which is added a Chapter on Distilla- 
tion, describing the process in operation at the Custom- House for 
ascertaining the Strength of Wines. By James B. Keene, of H. M. 

Customs. 8vo. $1 oc 

KELLEY.— Speeches, Addresses, and Letters on Industrial and 
Financial Questions : 
By Hon. William D. Kelley, M. C. 544 pages, 8vo. . S2.50 
KOENIG.— Chemistry Simplified: 

A Course of Lectures on the Non-Metals Based upon the Natural 
Evolution of Chemistry. Designed Primarily for Engineers. By 
George Augustus Koenig, Ph.D., A.M., E. M., Professor of 
Chemistry, Michigan College of Mines, Houghton. Illustrated by 
103 Original Drawings. 449 pp i2mo., (1906). . ^2.25 

KEMLO.— Watch-Repairer's Hand-Book : 
Being a Complete Guide to the Young Beginner, in Taking Apart. 
Putting Together, and Thoroughly Cleaning the English Lever and 
other Foreign Watches, and all American Watches. By F. Kemlo, 
•itactical Watchmaker. With Illustrations. i2mo. $J-2$ 



t6 HENRY CAREY BAIRD & CO.'S CATALOGUE. 

KENTISH.— A Treatise on a Box of Instruments, 

And the Slide Ruie ; with the Theory of Trigonometry and Logs 
rithms, including Practical Geometry, Surveying, Measuring of Tim. 
ber, Cask and Malt Gauging, Heights, and Distances. By Thoma' 
Kentish. In one volume. i2mo. . . . . ^JSl.OC 

KERL.— The Assayer's ManuaL- 

An Abridged Treatise on the Docimastic Examination of Ores, and 
Furnace and other Artitici .1 Products. By Bruno Kerl, Professor 
in the Royal School of Mines. Translated from the German by 
WiLi-iAM T. Brannt. Second American edition, edited with Ex- 
tensive Additions by F. LvNWOon Garrison, Mem.ber of the 
American Institute of Mining Engineers, etc. Illustrated hy 87 en- 
gravings. 8vo. (Third Edition in preparation. ) 
KICK. -Flour Manufacture . 
A Treatise on Milling Science and Practice. By Frederick Kick 
Imperial Regierungsrnth, Professor of Mechanical Technology in tlu 
imperial German Polytechnic Institute, Prague. Translated from 
the second enlarged and revised edition with supplement iiy H. H 
P. PoWLES, Assoc. Memb Institution of Civil Engineers. Illustrated 
with 28 Plaips, and 167 Wood-cuts. 367 pages. 8vo. . ;^io.oO 
RINGZETT.— The History, Products, and Processes of tho 
Alkali Trade : 
including the most Recent Improvements. By Chables Thomas 
yivr.7F.Tr Co"sn1iin'; Chemist. With 23 illustrations. 8vo. i^2.50 
KIRK. — The Cupola Furnace : 

A Practical ireatise on the i Onstruction and Management of Foundry 
Cupolas. By Edward Kirk, Practical Moulder and Melter, Con- 
sulting Expert in Melting. Illustrated by 78 engravings. Second 
Edition, revised and enlarged. 450 pages. 8vo. 1903. ^3-50 

LANDRIN.— A Treatise on Steel: 

Cumprising its Theory, Metallurgy, Properties, Practical Working, 
and iJse. By M. H. C. Landrin, Jr. From the French, by A. A, 

Fesquet. i2mo $2.sc 

LANGBEIN.— A Complete Treatise on the Electro-Deposl 
tion of Metals : 
Computing Electro-Plating and Galvanoplastic Operations, the De- 
position of Metals by the Contact and Immersion Processes, the Color- 
ing of Metals, the Methods of Grinding and Polishing, as well a? 
Description of the Voltaic Cells, Dynamo-Electric Machines, Ther- 
mopyles, and of the Materials and Processes Used in Every Depart- 
ment of the Art. Translated from tlie Fifth German Edition ot 
Dr. George Langbein, Proprietor of a Manufactory for Chemical 
Products, Machines, Apparatus and Utensils for Electro- Platers, and 
of an Electro-Plating Establishment in Leipzig. With Additions by 
William T. Brannt, Editoi of ''The Techno-Chemical Receipt 
Book." Sixth Edition, Revised and Enlarged. Illustrated by 163 
Engravings, 8vo , 725 pages (1909) . . . . . ^4 00 

LEHNER.— The Manufacture of Ink: 

Comprising the Raw Materials, and the Preparation of W«-;ting, 
Copying and Hekiograph Inks, Safety Inks, Ink Extracts and Pow- 
ders, etc. Translated from the German of SiGMUND Lehner, with 
additions by William T. Brannt, Illustrated. i2mo. ia.'oo 



HENRY CAREY BAIRD & CO.'S CATALOGUE 17 

*»— " ' . — ■ ~— — - — ■ 

L.ARKIN. — The Praciicai Brass and Iron Founder's Guide : 
A Concise Treatise on Brass Founding, Moulding, the Metals and 
their Alloys, etc.; lo vvnich are added Recent Improvements in the 
Manufacture of Iron, Steel by the Bessemer Process, etc., etc. Bj 
James Larkin, late Conductor of the Brass Foundry Department ii 
keany, Neafie & Co.'s Penn Works, Philadelphia. New editions 
revised, with extensive additions. 414 pages. i2mo. . S2.50 

LEROUX.— A Practical Treatise on the Manufacture of 
Worsteds and Carded Yarns : 
Comprising Practical Mechanics, with Rules and Calculations applied 
to Spinning; Sorting, Cleaning, and Scouring Wools; the Englisk 
and French Methods of Combing, Drawing, and Spinning Worsteds, 
and Manufacturing Carded Yarns. Translated from the French of 
Charles Leroux, Mechanical Engineer and Superintendent of a 
Spinning-Mill, by HoRATio Paine, M. D., and A. A. Fesquet, 
Chemist and Engineer. Illustrated by twelve large Plates. To whicb 
is added an Appendix, containing Extracts from the Reports of the 
International Jury, and of the Artisans selected by the Committe* 
appointed by the Council of the Society of Arts, London, on Woolet 
and Worsted Machinery and Fabrics, as exhibited in the Paris Uni- 
versal Exposition, 1867. 8vo. 54-00 

1-EFFEL.— The Construction of Mill-Dams : 

Comprising also the Building of Race and Reservoir Embankments 
and Head-Gates, the Measurement of Streams, Gauging of Water 
Supply, etc. By James Leffel & Co. Illustrated by 58 engravings 
Svo. (Scarce.) 

LESLIE.— Complete Cookery: 
Directions for Cookery in its Various Branches. By Miss Leslie. 
Sixtieth thousand. Thoroughly revised, with the addition of New 
Receipts. i2mo. ... . 5' !"> 

LE VAN. — The Steam Engine and the Indicator: 

Their Origin and Progressive Development; including the Mu.-t 
Recent Examples of Steam and Gas Motors, together with the liuii 
cator, its Principles, its Utility, and its Application. By William 
Barnet Le Van. Illustrated by 205 Engravings, chi;?fly of Indi 

cator-Cards. 469 pp. 8vo . ^2.00 

LIEBER.— Assayer's Guide : 
Or, Practical Directions to Assayers, Miners, and Smelters, for the 
Tests and Assays, by Heat and by Wet Processes, for the Ores of a'l 
0/ principal Metals, of Gold and Silver Coins aad Alloys, and of 
Coal, etc. By Oscar M. Lieber. Revised. 283 pp. I2mr.. ^1.50 
f^ockwood's Dictionary of Terms : 

Used in the Practice of Mechanical Engineering, embracing those 
Current in the Drawing Office, Pattern Shop, Foundry, Fitting, Turn- 
ing, Smith's and Boiler Shops, etc., etc., comprising upwards of Six 
Thousand Definitions. Edited by a Foreman Pattern Maker, authof 
jf " Patterr Making." 417 pp. l2mo. . . . $3.75 



l8 HENRY CAREY BAlRD & CO.'S CATALOGUE. 

LUKIN.— The Lathe and Its Uses: 

Or Instruciion in tlie Art of Turning Wood and Metal. Including 
a Description ol the Most Modern Appliances for the Ornamentation 
of Plane and Curved Surfaces, an Entirely Novl'I P^orm of Latiie 
for Eccentric and Rose-Engine Turning; A Lathe and Planing 
Macliine Combined; and Other Valuable Matter Relating to the 
Art. Illustrated by 462 engravings. Seventh edition. 315 pages. 
Svo #4.35 

HAIN and BROWN.— Questions on Subjects Connected with 

the Marine Steam-Engine : 

And Examination Papers; with Hints for their Solution. By 

Thomas J. Main, Professor of Mathematics, Royal "Caval College, 

and Thomas Brown, Chief Engineer, R. N. i2mo., cloth . ;^i.oo 

MAIN and BROWN. — The Indicator and Dynamometer: 
With their Practical Applications to the Steam-Engine. By Thomas 
J. Main, M. A. F. R., Ass't S. Professor Royal Naval College, 
Portsmouth, and Thomas Brown, Assoc. Inst. C. E., Chief Engineer 
R. N., attached to the R. N. College. Illustrated. Svo. . 

MAIN and BROWN.— The Marine Steam-Engine. 
By Thomas J. Main, F. R. Ass't S. Mathematical Professor nt the 
Royal Naval College, Portsmouth, and Thomas Brown, Assoc. 
Inst. C. E., Chief Engineer R. N. Attached to the Royal Naval 
College. With numerous illustrations. Svo. 

MAKINS.— A Manual of Metallurgy: 

By George Hogarth Makins. 100 engravings. Second edition 
rewritten and much enlarged. i2mo. 592 pages 

vffARTIN.— Screw-Cutting Tables, for the Use of Mechanic*) 

Engineers : 
Showing the Proper Arrangement of tVheels for Cutting the Threads 
of Screws of any Requued Pitch ; with a Table for Making the Uni 
versal Gas Pipe Thread and Taps. By W. A. Martin, Engineer. 
Svo. .<;o 

M ICHELL.- Mine Drainage : 

Being a Complete and Practical Treatise on Direct-Acting Under 
mund Steam Pumping Machinery. With a Description of a largt 
nvmber of the best known Engines, their General Utility and Ihe 
Special Sphere of their Action, the Mode of their Application, and 
their Merits compared with other Pumping Mnchinery. By STEPHEN 
MiCHElX. Illuslrated by 247 engravings. 8vo., 369 pages. 11250 

MOLESWORTH — Pocket-Book of Useful Formulae and 
Memoranda for Civil and Mechanical Engineers. 
By Guilford L. Molesworth, Member of the Institution of Civil 
Engineers, Chief Resident Engineer of the Ceylon Railway. Full- 
bound in Pocket-book form . . c - . . Jl 00 



ilENRY CAREY Bx\IRD & CO.'S CATALUGUIi, ^9 



MOORB.— The Universal Assistant and the Complete Wl 

chanic ; 

Containing over one million Industrial Facts, Calculations, Receiptfc. 
Processes, Trades Secrets, Rules, Business Forms, Legal Items, Etc., 
in every occupation, from the Household to the Manufactory. B| 
R. M<i(>RE. Illustrated by 500 Engravings. i2mo. . $2.yi 

MORRIS, — Easy Rules for the Measurement of Earthworks: 
By means of the Prismoidal Formjla, Illustrated with Numerour 
VVoed-Cuts, Problems, and Examples, and cunc'.udeti by an Exten 
sive Table for finding the Solidity in cubic yards from Mean Areas, 
The whole being adapted for convenient use by Engineers, Surveyors^ 
Contractors, and others needing Correct Measurements of Earthwork. 
By Elwood Morris, C. E. 8vo. . . . . . $i.$9 

MAUCHLINE.— The Mine Foreman's Hand-Book 

Of Practical and Theoretical I-.fonnation on the Opening, Ventl 
lating, and Working of Collieries. Questions and Answers on Prac. 
tical and Theoretical Coal Mining. Designed to Assist Students and 
Others in Passing Examinations for Mine Foremanships. By 
Robert Mauchline. 3d Edition. Thoroughly Revised and En- 
larged by F. Ernest Brackett. 134 engravings, 8vo. 378 pages. 
(1905) . $3.75 

NAPIER. — A System of Chemistry Applied to Dyeing. 
By James Napier, F. C. S. A New and Thoroughly Revised Edi- 
tion. Completely brought up to the present state of the Science, 
including the Chemistry of Coal Tar Colors, by A. A. Fesquet, 
Chemist and Engineer. With an Ap]3endix 0,1 Dyeing and Calico 
Printing, as shown at the Universal Exposition, Paris, 1867. Illus 
trated. 8vo. 422 pages ....... $2.50 

NEVILLE.— Hydraulic Tables, Coefficients, and FoimuI?e, fo' 
finding the Discharge of Water from Orifices, Notches 
Weirs, Pipes, and Rivers : 
Tiiird Edition, with Additions, consisting of New Formuise for tht 
>ischarge from Tidal and Flood Sluices and Siphons; general infor 
nation on Rainfall, Catchment-Basins, Drainage, Sewerage, Wa.e» 
Supply for Towns and Mill Power Bv Tohn Nevii.i.k. C. E. M P 
I. A. ; Fellow of the Royal Geological Society of Ireland. ThicJ 
l2mo. ........ Si:arce 

JEW^BERY.— Gleanings from Ornamental Art of every 
style : 
Drawn from Examples in the British, South Kensington, Indian, 
Crystal Palace, and other Museums, the Exhibitions of 1851 and 
1862, and the best English and Foreign works. In a series of loO 
exquisitely drawn F'lates, containing many hundred examples. By 
Robert Newberv. 410. ...... (Scaiccj 

NICHOLLS. —The Theoretical and Practical Boiler-Maker zn4 
Engineer's Reference Book: 
Containing a variety of Useful Information for Employers of Lat^r 
foremen a\d Workina; Boiler-Makers Iroo, Copper, and Tinsmith* 



20 HENRY CAREY BAIRD & CO.'S CAl'ALOGUE. 



IkaDghtsmen, Engineers, the General Steam-using Public, and for the 
Use of Science Schools and Classes. By SAMUEL NiCHOL.'.s. Illu» 
trated by sixteen plates, i2mo. ..... $2.^c- 

..NICHOLSON.— A Manual of the Art of Bookbinding -. 

Containing full instructions in the different Branches of Forwarding^ 
Gilding, and Finishing. Also, the Art of Marbling Book-edges and 
Paper. By James B. NICHOLSON. Illustrated. l2mo., cloth $2.25. 

NICOLLS.— The Railway Builder: 
A Hand-Book for Estimating the Probable Cost of American Rail* 
way Construction and Equipment. By WiLLiAM J. NicoLLS, Civil 
Engineer. Illustrated, full bound, pocket-book form . Scarce 

NORMANDY. — The Commercial Handbook of Chemical An»^ 
alysis : 
Or Practical Instructions for the Determination of the Intrinsic oi 
Commercial Value of Substances used in Manufactures, in Trades, 
and in the Arts. By A. Normandy. New Edition, Enlarged, and 
to a great extent rewritten. By Henry M. Noad, Ph.D., F.R.S.. 
thick i2mo. . Scarce 

NORRIS. — A Handbook fcr Locomotive Engineers and Ma 
chinists : 
Comprising the Proportions and Calculations for Constructing Loco 
motives; Manner of Setting Valves; Tables of Squares, Cubes, Areas^ 
etc., etc. By Septimus Norris, M. E. New edition. Illustrated, 
J2mo 5»-5c 

NYSTROM. — A New Treatise on Elements of Mechanics : 
Establishing Strict Precision in the Meaning of Dynamical Terms 
accorrpanied with an Appendix on Duodenal Arithmetic and Me 
trology. By John W. Nystrom, C. E. Illustrated. 8vo. 

NYSTROM.— On Technological Education and the Construc- 
tion of Ships and Screw Propellers : 
For Naval and Marine Engineers. By John V/. Nystrom, l^i. 
Acting Chief Engineer, U. S. N. Second edition, revised, with addi 
tional matter. Illustrated by seven engravings. i2mo. . $1.2^ 

O'NEILL. — A Dictionary of Dyeing and Calico Printing: 
Containing a brief account of all the Substances and PiocessesJ^. C 
use in the Art of Dyeing and Printing Textile Fabrics ; with Practrc^ 
Receipts and Scientific Information. By Charles O'Neill, Anal)" 
tical Chemist. To which is added an Essay on Coal Tar Colors ano 
their application to Dyeing and Calico Printing. By A. A. Fesquet 
Chemist and Engineer. With an appendix on Dyeing and Calic'> 
Printing, as shown at the Universal Exposition, Paris, 1867- 8vo.. 

491 pages . . $2.00 

ORTON. — Underground Treasures-. 

How and Where to Find Them. A Key for the Ready Determination 
<rf all the Useful Minerals within the United States. By jAMEi 
NiuN, A.M., Late Professor of Natural History in Vassar College^ 
N. Y ; author of the "Andes and the Amazon," etc. A New Edi- 
tion, with An Appendix on Ore Deposits and Testing Minerals (1901). 
Illustrated ........ ^I-SO 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 21 

OSBORN. — The Prospector's Field Book and Guide. 

In the Search For and the Easy Determination ot Ores and Other 
Useful Minerals. By Prof. H. S. Osborn, LL. D. Illustrated by 66 
Engravings. Seventh Edition. Revised and Enlarged. 379 pages, 

i2mo. (March, I907) $^-5° 

©SBORN — A Practical Manual of Minerals, Mines and Mm 
ing : 
Comprising the Physical Properties, Geologic Positions, Local Occur- 
rence and Associations of the Useful Mmerals; their Methods of 
Chemical Analysis-and Assay ; together with Various Systems of Ex- 
cavating and Timbering, Brick and Masonry Work, during Driving, 
Lining, Bracing and other Operations, etc. By Prof. 11. S. Osborn, 
LL. D., Author of " The Prospector's Field-Book and Guide." 171 
engravings. Second Edition, revised. 8vo. . . . M*5^ 
OVERMAN.— The Manufacture of Steel : 
Containing the Practice and Principles of Working and Making Steel. 
A Handbook for Blacksmiths and Workers in Steel and L-on, Wagon 
Makers, Die Sinkers, Cutlers, and Manufacturers of Files and Hard- 
ware, of Steel and Iron, and for Men of Science and Art. By 
Frederick Overman, Mining Engineer, Author of the " Manu- 
facture of lion," etc. A new, enlarged, and revised Edition. By 
A. A. FESQUfiT, Chemist and Engineer. i2mo. . . $i-SO 
OVERMAN.— The Moulder's and Founder's Pocket Guide : 
A Treatise on Moulding and Founding in Green-sand, Dry-sand, Loam, 
and Cement; the Moulding of Machine Frames, Mill-gear, Hollow- 
ware. Ornaments, Trinkets, Bells, and Statues; Description of Moulds 
for Iron, Bronze, Brass, and other Metals; Plaster of Pans, Sulphur 
Wax, etc. ; the Construction of Melting Furnaces, the Melting and 
Founding of Metals ; the Composition of Alloys and their Nature, 
etc., etc. By Frederick Overman, M. E. A new Edition, to 
which is added a Supplement on Statuary and Ornamental Moulding, 
Ordnance, Malleable Iron Castings, etc. By A. A. FesqueT, Chew 
iat and Engineer. Illustrated by 44 engravings. l2mo. . $2.<» 
PAINTER, GILDER, AND VARNISHER'S COMPANION. 
Comprising the Manufacture and Test of Pigments, the Arts of Pamt- 
ing. Graining, Marbling, Staining, Sign writing, Varnishing, Glass- 
staining, and Gilding on Glass ; together with Coacli Painting and 
Varnishing, and the Principles of the Harmony and Contrast of 
Colors. Twenty-seventh Edition. I'^evised, Enlarged, and in great 
part Rewritten. By William T. Brannt, Editor of " Varnishes, 
Lacquers, Printing Inks and Sealing Waxes." Illustrated. 395 pp. 

/2mo. . . . , ^150 

PALLETT.— The Miller's, Millwright's, and Engineer's Guide. 
By Henry Pallett. Illustrated. lamo. . . . $2.00 



82 riENRY CAREY BAIRD & CO.'S CATALOGUE. 



PERCY —The Manufacture of Russian Sh^et-lron. 

By John Percy, M. D , F. R. S. Paper, ... 25 cts. 
PERKINS.— Gas and Ventilation : 

Practical Treatise on Gas and Ventilation. Illustrated. I2mo. ^1.25 
PERKINS AND STOWE.— A New Guide to the Sheet-iron 
and Boiler Plate Roller : 
Containing a Series of Tal)les shnwintj the Weiglu of Slabs and Piles 
to Produce Boiler Plates, Ihd of the Weii,'ht ol Piles and the Sizes of 
Bars to produce Stieet-iron ; the Thickness of the Bar Gauge 
in decimals ; the Weight per foot, and the Thickness on the Bar or 
Wire Gauge of the fractional parts of an inch ; the Weight per 
sheet, and the Thickness on the Wire Gauge of Sheet-iron of various 
dimensions to weigh 112 lbs. per bundle; and the conversion of 
Short Weight into Long Weight, and Long Weight into Short. 

POSSELT. — Recent Improvements in Textile Machinery Re- 
lating to Weaving : 
Giving the Most Modern Points on the Construction of all Kinds 
of Looms, Warpers, Beamers, Slas'iCrs, Wimieis, Spoolers, Reeds, 
Temples, Shuttles, Bobbins, Heddles, Hedolle Frames, Pickers, 
Jacquards, Card Stampers, Etc., Etc. By E. A. Posselt. 410. 
Part I., 6co ills. ; Part IL, 60c ills. Each part . . . ^3.00 
Part III., 615 ills $7.50 

POSSELT. — Technology of Textile Design: 

The Most Complete Treatise on the Construction and Application 
of Weaves for all Textile Fabrics and the Analysis of Cloth. By E. 
A. Posselt. 1,500 illustrations. 410. .... $500 

POSSELT. — Textile Calculations: 

A Guide to Calculations Relating to the Manufacture of all Kinds 
of Yarns and Fabrics, the Analysis of Cloth, Speed, Power atid Belt 
Calculations. By E. A. PosSELT. Illustrated. 4to. . ;g2.oo 

REGNAULT.— Elements of Chemistry: 

By M. V. Regnault. Translated from the French by T. Forrest 
Betton, M. D., and edited, with Notes, by James C. Booth, Melter 
and Refiner U. S. Mint, and William L. Faber, Metallurgist and 
Mining Engineer. Illustrated by nearly 700 wood-engravings. Com- 
prising nearly 1,500 pages. In two volumes, 8vo., cloth . 36.00 
RICHARDS.— Aluminium : 

Its History, Occurrence, Properties, Metallurgy and Applications, 
inclutling its Alloys. By Joseph W. Richards, A. C, Chemist and 
Practical Metallurgist, Member of the Deutsche Chemische Gesell- 
schaft. Illust. Third edition, enlarged and revised (1895) . ^6.O0 
felFFAULT, VERGNAUD, and TOUSSA7NT.— A Practical 
Treatise on the Manufacture of Colors for Painting : 
Comprising the Origin, Definition, and Classification of Colors; the 
Treatment of the Raw Materials; the best Formulae and the Newest 
Processes for the Preparation of every description of Pigment, and 
the Necessary Apparatus and Directions for its Use; Dryers; the 
Testing, Application, and Qualities of Paints, etc., etc. By MM. 
RlFFAULT, Vergnaud, and ToussAiNT. Revkod aad Edited by M 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 



F. Malepeyre. Trans.ated from the French, by A. A. FesQOK^ 
Chemist and Engineer. Illustrated by Eighty engravings. In one' 
vol., 8vo., 659 pages .....•■ $3-*^ 

ROPER. — Catechism for Steam Engineers and Electricians: 

Including the Constiuction and Management of Steam Engines, 
Steam Boilers and Electric Plants. By Stephen Roper. Twenty- 
first edition, rewritten and greatly enlarged by E. R. Keller and 
C. W. Pike. 365 pages. Illustrations. i8mo., tucks, gilt. $2.00 

ROPER.— Engineer's Handy Book: 

Containing Facts, Formula;, Tables and Questions on Power, its 
Generation, Transmission and Measurement; Heat, Fuel, and Steam; 
The Steam Boiler and Accessories ; Steam Engines and their Parts ; 
Steam Engine Indicator ; Gas and Gasoline Engines ; Materials ; 
their Properties and Strength ; Together with a Discussion of the Fun- 
damental Experiments in Electricity, and an Explanation of Dynamos, 
Motors, Batteries, etc., and Rules for Calculating Sizes of Wires. By 
Stephen Roper. I5ih edition. Revised and enlarged by E. R. 
Keller, M. E. and C. W. Pike, B. S. (1899), with numerous illus- 
trations. Pocket-book form. Leather $3'$^ 

ROPER. — Hand-Book of Land and Marine Engines : 
Including the Modelling, Construction, Running, and Management 
of Lanf' and Marine Engines and Boilers. With illustrations. By 
Stephen Roper, Engineer. Sixth edition. i2mo.,t\'cks, gilt edge. 

^3-50 
ROPER.— Hand-Book of the Locomotive : 

Including the Construction of Engines and Boilers, and the Construc- 
tion, Management, and Running of Locomotives. By Stephen 
Roper. Eleventh edition. iSmo., tucks, gilt edge . $2.50 

ROPER. — Hand-Book of Modern Steam Fire-Engines. 
AVith illustrations. By STEPHEN RoPER, Engineer. Fourth edition, 

l2mo., tucks, gilt edge $3-SC 

ROPER. — Questions and Answers for Engineers. 

This little book contains all the Questions that Engineers will be 
asked when undergoing an Examination for the purpose of procuring 
Licenses, and they are so plain that any Engineer or Fireman of or 
dinary intelligence may commit them to memory in a short time. By 
Stephen Roper, Engineer. Third edition . . . ^2.00 
ROPER.— Use and Abuse of the Steam Boiler. 

By Stephen Roper, Engineer. Eighth edition, with illustrations, 
l8mo., tucks, gilt edge ,...,.. ^9^2,00 
ROSE. — The Complete Practical Machinist : 

Embracing Lnthe Work, Vise Work, Drills and Drillmg, Taps and 
Dies, Hardening and Tempering, the Making and Use of Tools 
Tool Grinding, Marking out Work, Machine Tools, etc. By JoSHUA 
UosF,. 39; Engravings. Nmeteenih Edition greatly Enlarged with 
New and Valuable Matter. l2mo., 504 pages. . . ^2.50 

ROSE— Mechanical Drawing Self-Taught : 

Comprising Iii^lruciinns in the .St-icciion and Preparation of Drawing 
instruments, El n' niaiv Tnstr.iction in Practical Mechanical Draw- 



«4 HENRY CAREY BAIRD & CO.'S CATALOGUE. 

ing, together with Examples in Simple Geometry and Elementary 
Mechanism, including Screw Threads, Gea-r Wheels, Mechanical 
Motions, Engines and Boilers. By JosHUA RoSE, M. E. Illustrated 
by 330 engravings. 8vo ,313 pages .... jt4.cx) 

ROSE.— The Slide- Valve Practically Explained: 

Embracing simple and complete Practical Demonstrations of th, 
operation of each element in a Slide-valve Movement, and illustrat- 
ing the effects of Variations in their Proportions by examples care- 
fully selected from the most recent and successful practice. By 
Joshua Rose, M. E. Illustrated by 35 engravings . $1.00 

ROSS. — The Blowpipe in Chemistry, Mineralogy and Geology: 

Containing all Known Methods of Anhydrous Analysis, many Work- 
ing Examples, and Instructions for Making Apparatus. By LiEUT.- 
CoLONEL W. A. Ross, R. A., F. G. S. With 120 Illustrations. 
i2mo. .......... ^2.00 

SHAW.— Civil Architecture : 

Being a Complete Theoretical and Practical System of Building, con- 
taining the Fundamental Principles of the Art. By Edward Shaw, 
Architect. To which is added a Treatise on Gothic Architecture, etc. 
By Thomas W. Sili.oway and George M. Harding, Architects. 
The whole illustrated by 102 quarto plates finely engraved on copper. 
Eleventh edition. 4to. $6.QO 

SHUNK. — A Practical Treatise on Railway Curves and Loca 
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By W. F. Shunk, C. E. i2mo. Pull bound pocket-book form $2.<x 

SLATER.— The Manual of Colors and Dye Wares. 

By J. W. Slater. i2mo $3-oo 

SLOAN. — American Houses : 

A variety of Original Desij^ns for Rural Buildings. Illustrated by 
26 colored engravings, with descriptive references. By Samuel 
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SLOAN. — Homestead Architecture: 

C'jntainir.g Forty Designs for Villas, Cottages, and Farm-houses, with 
Ei^^says on Style, Construction, Landscape Gardening, Furniture, etc., 
etc. JHustrated by up'vards of 200 engravings. By Samuel Sloan, 
Architect. 8vo ^82.50 

6LOANE. — Ho.r^e Experiments m Science. 

By T. O'CoNOR Slc\ne, E. M., A.M., Ph.D. Illustrated by 91 
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SMEATON. — Builder's Pocket -Companion : 

» Containing the Elements of Building, Surveying, and Architecture; 
with Practical Rules and In'^tructions coi:'iected with the subject. 
By A. C. Smeaton, Civil Engineer, etc. i2mo. 

SMITH.- A Manual of Political Economy. 

By E. Peshine Smith. A New Edition, to which is added a full 
Index. i2mo . ..... |>I 25 



frlEiNkV CAKtY ii/vlKij ^^ c^. cs k,. . i . > t^vjv^ UE. 25 

SMITH— Parks and Pleasure-Grounds : 

Or Practical Notes on Country Residences, Villas, Public Parks, and 
Gardens. By Charles H. J. Smith, Landscape Gardener and 
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SMITH.— The Dyer's Instructor: 

Comprising Practical Inst<-uctions in the Art of Dyeing Silk, Cotton, 
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Receipts. To which is added a Treatise on the Art of Padding; and 
t'le Printing of Silk Warps, Skeins, and Handkerchiefs, and the 
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:;/ David S.MITH, Pattern Dver. i2mo. . . . $1.00 

8 /lYTH.— A Rudimentary Treatise on Coal and Coal-Mining. 
By Warrington \V. Smyth, M. A., F. R. G., President R. G. S. 
of Cornwall. Fifth edition, revised and corrected. With fiumer* 
ous illustrations. l2mo. ...... ^^1.40 

SNIVELY.— Tables for Systematic Qualitative Chemical Anal- 
ysis. 
By John H. Snively, Phr. D. 8vo. .... $1.00 

SNIVELY.— The Elements of Systematic Qualitative vhemical 
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A Hand-book for Beginners. By JoHN H. Snively, Phr. D. i6mo. 

;^2.oo 

STOKES. — The Cabinet Maker and Upholsterer's Companion: 
Comprising the Art of Drawing, as applicable to Cabinet Work; 
Veneering, Inlaying, and Buhl-Work; the Art of Dyeing and Stain 
ing Wood, Ivory, Bone, Tortoise-Shell, etc. Directions for Lacker- 
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Cements, and Compos'.^^ns; with numerous Receipts, useful to work 
men generally. B'- Stokes. Illustrated. A New Edition, with 
an Appendix upor .ench Polishing, Staining, Imitating, Varnishing, 
etc., etc. i2nio ........ ^1.25 

STRENGTH AND OTHER PROPERTIES OF METALS; 
Reports of Experiments on the Strength and other Properties of 
Metals for Cannon. With a Description of the Machines for Testing 
Metals, and of the Classification of Cannon in service. By Officer? 
of the Ordnance Department, U. S. Army. By authority of the Secre- 
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SULLIVAN. — Protection to Native Industry. 

By Sir Euward Sullivan, Baronet, author of " Ten Chapters on 
Social Reforms." 8vo. ....... ^i.oo 

SHERRATT.— The Elements of Hand-Railing: 

Simplified and Explained in Concise Problems that are Easily Under- 
stood. The whole illustrated with Thirty-eight Accurate and Origi- 
nal Plates, Founded on Geometrical Principles, and Showing how'to 
Make Rail Without Centre Joiiit.s, Making Better Rail of the Same 
Material, with Half the LaWor, and Showing How to Lay Out Stairs 
of all Kinds. By R. J. Shekratt. Folio. . . . ^2.50 



26 HENRV CAREY BAIRu & CO.'S CATALOGUE. 

SYME.— Outlines of an Industrial Science. 

By David Syme. i2mo, . . ... $2.0C 

TABLES SHOWING THE WEIGHT OF ROUND, 
SQUARE, AND FLAT BAR IRON, STEEL, ETC., 

By Measurement. Clolh ...... 63 

THALLNER.— Tool-Steel : 

A Concise Handbook 011 Tool-Steel in General. Its Treatment In 
the Operations of Forging, Annealing, Hardening, Tempering, etc., 
and the Appliances Therefor. By OiTO Thallner, Manager ia 
Chief of the Tool-Steel Works, Bismarck liiitte, Germany. From the 
German by WiLLIAM T. BrannT. Illustrated by 69 engravings. 
194 pages. 8vo. 1902. |2.oo 

TEMPLETON. — The Practical Examinator on Steam and thi 

Steam -Engine: 

With Instructive References relative thereto, arranged for the Use of 

Engineers, Students, and others. By WiLLiAM TEMPLETON, En. 

gineer. i2mo. ....•••. ^i-OO 

THAUSING.— The Theory and Practice of the Preparation of 
Malt and the Fabrication of Beer: 
With especial reference to the Vienna Process of Brewing. Elab- 
orated from personal experience by JUJ..IUS E. Thausing, Professor 
at the School for Brewers, and at the Agricultural Institute, Modling, 
near Vienna. Translated from the German by WiLLlAM T. BrannT, 
Thoroughly and elaborately edited, with much American matter, and 
according to the latest and most Scientific Practice, by A. ScHWARZ 
and Dr. A. H. Bauer. Illustrated by 140 Engravings. 8vo., 815 
pages .......... ^10.00 

THOMPSON. — Political Economy. With Especial Reference 
to the Industrial History of Nations : 
By Robert E. Thompson, M. A., Professor of Social Science in the 
University of Pennsylvania. i2mo. .... ^1.50 

THOMSON.— Freight Charges Calculator: 

By Andrew Thomson, Freight Agent. 24mo. , . ^1.25 

TURNER'S (THE) COMPANION: 
Containing Instructions in Concentric, Elliptic, and Eccentric Turn- 
ing; also various Plates of Chucks, Tools, and Instruments; and 
Directions for using the Eccentric Cutter, Drill, Vertical Cutter, and 
rrircular Rest; with Patterns and Instructions for working them. 
l2mo. .......... ^I.OO 

TURNING : Specimens of Fancy Turning Executed on the 

Hand or Foot-Lathe : i 

With Geometric, Oval, and Eccentric Chucks, and Elliptical Cutting 

Frame. By an Amateur. Illustrated by 30 exquisite Photographs. 

4to. . (Scarce.) 



HENRY CAREY BAIRD & CO.'S CATALOGUE. a; 



V^AILE.— Galvanized-Iron Cornice-Worker's Manual : 

Containing Instructions in Laying out the Different Mitres, and 
Making Patterns for all kinds of Plain and Circular Work. Also 
Tables of Weights, Areas and Circumferences of Circles, and other 
Matter calculated to Benefit the Trade. By Charles A. Vaile. 
Illustrated by twenty-one plates. 410. . . .(Scarce.) 

VILLE. — On Artificial Manures : 

Their Chemical Selection and Scientific Application to Agriculture. 
A series of Lectures given at the Experimental Farm at Vincennes, 
during 1867 and 1874-75. By M. Georges Ville. Translated and 
Edited by William Crookes, F. R. S. Illustrated by thirty-one 
engravinos. 8vo., 450 pages ^6.00 

VILLE.— The School of Chemical Manures : 
Or, Elementary Principles in the Use of Fertilizing Agents. From 
the French of M. Geo. Ville, by A. A. Fesquet, Chemist and En- 
gineer. With Illustrations. l2mo. .... ;^l.2^ 

VOGDES.— The Architect's and Builder's Pocket- Companioo 
and Price-Book : 

Consisting of a Shoit but Comprehensive Epitome of Decimals, Duo- 
decimals, Geometry and Mensuration; with Tables of United Stales 
Measures, Sizes, Vveights, Strengths, etc., of Iron, Wood, Stone, 
3rick, Cement and Concretes, Quantities of Materials in given Sizes 
and Dimensions of Wood, Brick and Stone; and full and complete 
Bills of Prices for Carpenter's Work and Painting; also. Rules for 
Computing and Valuing Brick and Brick Work, Stone Work, Paint- 
ing, Plastering, with a Vocabulary of Technical Terms, etc. By 
Frank W. Vogdes, Architect, Indianapolis, Ind. Enlarged, revised, 
and corrected. In one volume, 368 pages, full-bound, pocket-book 
form, gilt edges ........ ^2.00 

Cloth . . 1.50 

VAN CLEVE.— The English and American Mechanic: 

Com|3risiiig a Collection of Over Three Thousand Receipts, Rules, 
and Tables, designed for the Use of every Mechanic and Manufac- 
turer, By B. Frank Van Cleve. Illustrated. 500 pp. i2mo. ^2.00 
VAN DER BURG.— School of Painting for the Imitation of 
Woods and Marbles : 
A Complete, Practical Treatise on the Art and Craft of Graining and 
Marbling with the Tools and Appliances. 36 plates. Folio, 12x20 
inches. ......... $6.00 

WAHNSCHAFFE.— A Guide to the Scientific Examinatioe 
of Soils : 
Comprising Select Methods of Mechanical and Chemical A lalysu^ 
and Physical Investigation. Translated from the German of Dr. F. 
Wahnschaffe. With additions by William T. Brannt. Illus- 
trated by 25 engravings. i2mo. 177 pages . . . $l-Sfi 
IVALTON. — Coal-Mining Described and Illustrated: 

By Thomas H. Walton, Mining Engineer. Illustrated by 24 Jast^ 
and elaborate Plates, after .(Xctual Workings and Apparatus. |2.oo 



2^ HENRY CAREY BAIRD & CO.'S CATALOC UE. 

WARE.— The Sugar Beet. 

Including a History of the Beet Sugar Industry in Europe, Vanetiei 
of the Sugar Beet, Examination, Soils, Tillage, Seeds and Sowing, 
Yield and Cost of Cultivation, Harvesting, Transportation, Conserva 
tion, Feeding Qualities of the Beet and of the Pulp, etc. By Lewh 
S. Ware, C. E., M. E. Iliustiated by ninety engravings. 8vo. 

WARN.— The Sheet-Metal Worker's Instructor: 

For Zinc, Sheet-Iron, Copper, and Tin-Plate Workers, etc. Contain- 
ing a selection of (jeonietrical Problems ; also. Practical and Simple 
Rules for Describing the various Patterns required in the different 
branches of the above Trades. By Reuben H. Warn, Practical 
Tin- Plate Worker. To which is added an Appendix, containing 
Instructions lor Boiler-Making, Mensuration of Surfaces and Solids, 
Rules for Calculating the Weights of different Figures of Iron and 
Steel, Tables of the Weights of Iron, Steel, etc. Illustrated by thirty- 
two Plates and 'hirty-seven Wood Engravings. 8vo. . ^^2.50 

WARNER.— New Theorems, Tables, and Diagrams, for tht 
Computation of Earth-work : 

Designed for the u^e of Engineers in Preliminary and Final Estimates 
of Students in Engineering, and of Contractors and other non-profes- 
sional Computers. In two parts, with an Appendix. Parti. A Prac- 
tical Treatise; Part II. A Theoretical Treatise, and the Appendix, 
Containing Notes to the Rules and Examples of Part I.; Explana 
tions of the Construciion nf Scale'^, T.ible>, and Diagrams, and j 
Treatise upon Equivalent hquare Bases and Equivalent Level Heights 
By John Warner, A. M., Mining and Mechanical Engineer. Illus- 
1 ated by 14 Plates. Svo. ...... $3.00 

WILSON. — Carpentry and Joinery : 

By John Wilson, Lecturer on Building Construction, Carpentry and 
Joinery, etc., in the Manchester Technical School. Third Edition, 
with 65 full-page plates, in flexible cover, oblong. . . (Scarce.) 

WATSON— A Manual of the Hand.Lathe : 

Comprising Concise Directions for Working Metals of all kinds, 
Ivory, Bone, and Precious Woods ; Dyeing, Coloring, and French 
Polishing ; Inlaying by Veneers, and various methods practised to 
produce Elaborate work with Dispatch, and at Small Expense. By 
Egbert P. Watson, Author of "The Modern Practice of American 
Machinists and Engineers " Illustrated by 78 engravings. $1.50 

WATSON. — The Modern Practice of American Machinists 
and Engineers : 

Including the Construction, Application, and Use of Drills, Lathe 
Tools, Cutters for Boring Cylinders, and Hollow-work generally, with 
the most Economical Speed for the same ; the Results verified by 
. Actual Practice at the Lathe, the Vise, and on the floor. Togethei 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 29 

with Workslinp Management, Economy of Manufacture, the Steam 
Engine, Boilers, Gears, Belting, etc., etc. By Egbert P. V\ atson. 
Illustra'ed hy eighty-six engravings. i2mo. . . . $2.50 

WATT.— The Art of Soap Making: 

A Practical Iland-Book of the Manufacture of Hard and Soft Soaps, 
Toilet Soaps, etc. Fifth Edition, Revised, to which is added an 
Appendix on Modern Candle Making. By Alexander Watt. 
111. I2nio. S3. 00 

WEATHERLY.— Treatise on the Art of Boiling Sugar, Crys- 
tallizing, Lozenge-making, Comfits, Gum Goods, 
And other processes for Confectionery, including Methods for Manu- 
facturing every Description of Raw and Refined Sugar Goods. A 
New and Enlarged Edition, with an Appendix on Cocoa, Chocolate, 
Chocolate Confections, etc. 196 pages, 1 2mo. (1903) . i^i.So 

WILL. — Tables of Qualitative Chemical Analysis • 

With an Introductory Chapter on the Course of /Analysis. By Pro- 
fessor Heinrich Will, of Giessen, Germany. Third American, 
from the eleventh German edition. Edited by Charles F. Himes, 
Pli. D., Professor uf Natural Science, Dickinson College, Carlisle, 
Pa. 8vo ^1.50 

WILLIAMS.— On Heat and Steam : 

Embracing New Views of Vaporization, Condensation and Explo- 
sion. By Charles Wye Williams, A. I. C. E. Illustrated. 8vo. 

J2.50 

WILSON — First Principles of Political Economy: 

Witli Reference to Statesmanship and tiie Progress of Civilization. 
By Professor W. D. WiLSON, of the Cornell University. A new and 
revised edition. l2mo. . . . . . . ^I-S^ 

WILSON. — The Practical Tool-Maker and Designer: 

A Treatise upon tlie Designing of Tools and Fixtures for Machine 
Tools and Metal Working Machinery, Comprising Modern Examples 
of Machines with Fundamental Designs for Tools for the Actual Pro- 
duction of the work ; Together with Special Reference to a Set of 
Tools for Machining the Various Parts of a Bicycle. Illustrated by 
189 engravings. 1898. ...... $2.50 

CONTENTS: Introductory. Chapter I. Modern Tool Room and Equipment. 
II. Files, Their Use and Abuse. III. Steel and Tempering. IV. Making Jigs. 
V. Milling Machine Fixtures. VI. Tools and Fixtures fur Screw Machines. Vll. 
Broaching. VIII. Punches and Dies for Cutting and Drop Press. IX.Toolsfor 
Hollow-Ware. X. Embossing: Metal, Coin, and Stamped Sheet-Metal Orna- 
ments. XI. Drop Forging. XII. Solid Drawn Shells or Ferrules ; Cupping or 
Cutting, and Drawing; Breaking Down Shells. XIII. Annealing, Pickling, and 
Cleaning, XIV. Tools for Draw Bench. XV. Cutting and Assemblirg Pieces 
by Means of Ratchet Dial Plates at One Operation. XVI. The Header. XVII 
Tools for Fox Lathe. XVIII. Suggestions for a Set of Tools for Machining the 
Various Parts of a Bicycle. XIX. The Plater's Dynamo. XX. Conclusion — 
With a Few Random Ideas. Appendix. Index. 

WOODS — Compound Locomotives : 

By Arthur Tannatt Woods. Second edition, revised and enlarged 
by David Leonard Barnes, A. M., C. E. 8vo. 330 pp. $3.00 



30 HENRY CAREY BAIRD & CO.'S CATALOGUE. 

WOHLER. — A Hand-Bookof Mineral Analysis: 

By F. WoHLER, Professor of Chemistry in the University of Gottin- 
gen. Edited by Henry B. Nason, Professor of Chemistry in the 
Renssalaer Polytechnic Institute, Troy, New York. Illustrated. 
i2nio. $2.50 

WORSSAM.— On Mechanical Saws: 

From the Transactions of the Society of Engineers, 1869. By S. W. 
WoRSSAM, Jr. Illustrated by eighteen large plates. 8vo. $1.50 



RECENT ADDITIONS. 

BRANNT. — Varnishes, Lacquers, Printing Inks and Sealing. 
Waxes : 

Their Raw Materials and their Manufacture, to which is added the 
Art of Varnishing and Lacquering, including the Preparation of Put- 
ties and of Stains for Wood, Ivory, Bone, Horn, and Leather. By 
William T. Brannt. Illustrated by 39 Engravings, 338 pages. 
i2mo ^3.00 

BRANNT.— The Practical Dry Cleaner, Scourer, and Gar- 
ment Dyer : 
Comprising Dry or Chemical Cleaning; Purification of Benzine; Re- 
moving Stains or Spotting; Wet Cleaning; Finishing Cleaned Fabrics; 
Cleaning and Dyeing Furs, Skins, Rugs, and Mats; Cleaning and 
Dyeing Feathers ; Bleaching and Dyeing Straw Hats ; Cleaning and 
Dyeing Gloves; Garment Dyeing; Stripping; Analysis of Textile 
Fabrics. Edited by William T. Brannt, Editor of "The Techno- 
Chemical Receipt Book." Third Edition, Revised and Enlarged. 
Illustrated by Twenty-Three Engravings ^2 50 

BRANNT.— Petroleum , 
its History, Origin, Occurrence, Production, Physical and Chemical 
Constitution, Technology, Examination and Uses; Together with 
the Occurrence and Uses of Natural Gas. Edited chiefly from the 
German of Prof. Hans Hoefer and Dr. Alexander Veith, by W'M. 
T. Brannt. Illustrated by 3 Plates and 284 Engravings. 743 pp. 
8vo, #8.50 

BRANNT. — A Practical Treatise on the Manufacture of Vine- 
gar and Acetates, Cider, and Fruit-Wines ; 
Preservation of Fruits and Vegetables by Canning and Evaporation; 
Preparation of Fruit-Butters, Jellies, Marmalades, Catchups, Pickles, 
Mustards, etc. Edited from various sources. By WiLLlAM T. 
Brannt. Illustrated by 79 Engravings. 479 pp. 8vo. $S-oo 

BRANNT.— The Metal Worker's Handy-Book of Receipts 
and Processes : 

Being a Collection of Chemical Formulas and Practical Manipula- 
tions for the working of all Metals; including the Decoration and 
Beautifying of Articles Manufactured therefrom, as well as their 
Preservation. Edited from various sources. By William T. 
Brannt. Illustrated. i2mo. I2.50 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 31 

DEITE. — A Practical Treatise on the Manufacture of Per- 
fumery : 

Comprising directions for making all Kinds of Perfumes, Sachet 
Powders, Fumigating Materials, Dentifrices, Cosmetics, etc., with a 
full account of the Volatile Oils, Balsams, Resins, and other Natural 
and Artificial Perfume-substances, including the Manufacture of 
Fruit Ethers, and tests of their purity. By Dr. C. Deite, as^^isted 
by L. BoRCHERT, F. Eichbaum, E. Kugler, H. Toeffner, and 
other experts. From the German, by Wm. T. Brannt. 28 Engrav 

ings. 358 pages. 8vo. $3*30 

EDWARDS. — American Marine Engineer, Theoretical and 
Practical : 
With Examples of the latest and most approved American Practice. 
By Emory Edwards. 85 illustrations. lamo. . . ^2.00 

EDWARDS.— 900 Examination Questions and Answers: 

For Engineers and Firemen (Land and Marine) who desire to ob- 
tarn a United States Government or State License. Pocket-book 

form, gilt edge ^^-5° 

FLEMMING. — Practical Tanning: 

A Handbook of Modern Processes, Receipts, and Suggestions for the 
Treatment of Hides, Skins, and Pelts of Every Description. By 
Lewis A. Flsmming. American Tanner. 472 PP- 8 vo. (1903) ^4.00. 
POSSELT. — The Jacquard Machine Analysed and Explained: 
With an Appendix on the Preparation of Jacquard Cards, and 
Practical Hints to Learners of Jacquard Designing. By E. A. 
PossELT. With 230 illustrations and numerous diagrams. 127 pp. 

4to $300 

POSSELT. — Recent Improvements in Textile Machinery, 
Part III: 
Processes Required for Converting Wool, Cotton, Silk, from Fibre 
to Finished Fabric, Covering both Woven and Knit Goods ; Con- 
struction of the most Modern Improvements in Preparatory Machin- 
ery, Carding, Combing, Drawing, and Spinning Machinery, Winding, 
Warping, Slashing Machinery Looms, Machinery for Knit Goods, 
Dye Stuffs, Chemicals, Soaps, Latest Improved Accessories Relat- 
ing to Construction and Equipment of Modern Textile Manufactur- 
ing Plants. By E. A, Possf.lt. Comoletel" Illustrated. 4to. 

^7-50 
RICH.— Artistic Horse.Shoeing: ^ ,^ ^ ^ . 

A Practical and Scientific Treatise, givmg Improved Methods of 
ShoeinP with Special Directions foi Shaping Shoes to Cure Different 
Disease's of the Foot, and for the Correction of Faulty Action in 
Trotters By George E, "i'm r.2 Ilhisiu.tions. 153 pa-es 

' 2.00 



32 HENRY CAREY BAIRD & CO.'S CATALOGUE. 



RICHARDSON. -Practical Blacksmithing : 

A Callection of Articles Contributed at Different Times by Skilled 
Workmen to the columns of " The Blacksmith and Wheelwright," 
and Covering nearly the Whole Range of Blacksmithing, from the 
Simplest Job of Work to some of the Most Complex Forgings. 
Compiled and Edited by M. T. Richardson. 

Vol.1. 2IO Illiistraiions. 224 pages. i2mo. . . ^Jl.oo 
Vol. II. 230 Illustrations. 262 pages. l2mo. . , $l.oo 
Vol. III. 390 Illustrations. 307 pages. i2mo. , , ^Sl.oo 
Vol. IV. 226 Illustrations. 276 pages. I2mo. , , |i.oo 
RICHARDSON.'— The Practical Horseshoer; 
Being a Collection of Articles on Horseshoeing in all its Branches* 
which have appeared from time to time in the columns of " 1 he 
Blacksmith and Wheelwright," etc. Compiled and edited by M. T. 
Richardson. 174 illustrations ^i.oo 

ROPER. — Instructions and Suggestions for Engineers and 
Firemen : 
By Stephen Roper, Engineer. i8mo. Morocco . $2.00 

ROPER.— The Steam Boiler: Its Care and Management: 
By Stephen Roper, Engineer. i2mo., tuck, gilt edges. ;^2.oo 

ROPER.— The Young Engineer's Own Book: 

Containing an Explanation of the Principle and Theories on which 
the Steam Engine as a Prime Mover is Based. By Stephen Roper, 
Engineer. 160 illustrations, 363 pages. i8mo., tuck . '82. 50 

ROSE. — Modern Steam- Engines: 
An Elementary Treatise upon the Steam-Engine, written in Plain 
language ; for Use in the Workshop as well as in the Drawing Office. 
Giving Full Explanation J of the Construction of Modern Steanv 
Engines : Including Diagrams showing their Actual operation. To. 
gether with Complete but Simple Explanations of the operations of 
Various Kinds of Valves, Valve Motions, and Link Motions, etc., 
thereby Enabling the Ordinary Engineer to clearly Understand the 
Principles Involved in their Construction and Use, and to Plot out 
their Movements upon the Drawing Board. By Joshua Rose. M. E. 
Illustrated by 422 engravings. Revised. 358 pp. . . ;5!6.oo 

ROSE.— Steam Boilers: 
A Practical Treatise on Boiler Construction and Examrnation, for the 
Use of Practical Boiler Makers, Boiler Users, and Jjispectors; and 
embracing in plain figures all the calculations necessary in Designing 
or Classifying Steam Boilers. By Joshua Rose, M. E. Illustrated 
by 73 engravings. 250 pages. 8vo. .... 152.50 

8CHRIBER. — The Complete Carriage and Wagon Painter: 
A Concise Compendium of the Art of Painting Carriages, Wagons, 
and Sleighs, embracing Full Directions m all the Various Branches, 
including Lettering, Scrolhng, Oman;enting, Striping, Varnishing, 
and Coloring, with numerous Recipes for Mixing Colors. 73 Illus- 
trations. 177 pp. i2mo. ...... $iJOr 



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